Preface

The United States is at an inflection point. America’s borders are overrun, and our homeland is more exposed to enemy missiles, cyberattacks, and sabotage than at any time in recent history—if ever. At the same time, our greatest foreign threat—the People’s Republic of China—is on a warpath in the Indo-Pacific and has a credible chance not only of seizing Taiwan, but also of dominating the entire region. Russia’s invasion of Ukraine is a harbinger of worse to come if our NATO allies do not take the lead in Europe’s defense. Israel is beset by threats from all directions, and Iran may be only weeks away from producing a nuclear weapon. And North Korea is as belligerent as ever but now increasingly capable of striking the U.S. homeland with nuclear weapons.

Conservatives recognize the need for a strong national defense. This is both a constitutional mandate and a vital part of America’s conservative tradition, and it is one we must and will uphold, especially as the world grows more dangerous. Yet it is equally conservative to do so with clear-eyed clarity about the realities facing us today.

In the years since the end of the Cold War, Washington has behaved as though America’s military power, financial resources, and political will are unlimited, from the Iraq invasion to nation-building in Afghanistan and the Biden Administration’s expansive and incoherent policies in Europe, the Middle East, and the Indo-Pacific today. And the results have been tragic: thousands of American lives lost, tens of thousands of Americans injured, and trillions of dollars spent—and still being spent—abroad on goals that are closer to globalist liberalism than they are to true conservatism. Meanwhile, as The Heritage Foundation’s 2024 Index of U.S. Military Strength demonstrates, what advantages the U.S. military enjoyed in the 1990s have severely eroded because of our distractions, leaving our forces hard-pressed to deter China, to say nothing of multiple adversaries at once. Five years ago, talk of a third world war might have been considered hyperbole. Today, it is a real possibility—unless we adopt a different approach.

Fortunately, we can draw inspiration from conservative leaders during the Cold War. Ronald Reagan, Richard Nixon, and Dwight Eisenhower all confronted dangerous threats abroad. But they also recognized what U.S. forces could and could not realistically be expected to do in confronting those threats and prioritized accordingly. These were serious men who took security seriously—with realism, not posturing. President Reagan built up America’s military—but he concentrated U.S. forces in Europe, the heart of our competition with the Soviet Union, and canonized the Weinberger Doctrine. President Nixon similarly elevated the Soviets over other threats, most famously in his decision to open up to China. President Eisenhower did likewise by rejecting calls for America to go to war in Indochina and Hungary and by focusing U.S. forces instead on containing the Soviets in Europe, playing to our strengths with his New Look rather than to the Soviets’ tune. All of them expected allies to do their part and were willing to press the issue to make sure they did.

Now it is time to adopt this tried-and-true American conservative realism again, and The Heritage Foundation is proud to lead the way. In this Special Report, you will find a proposed defense strategy that prioritizes defending the American homeland and denying China’s imperial ambitions while empowering U.S. allies and partners to lead against lesser threats with more limited U.S. support. Under this strategy, Americans can be confident in the ability of U.S. forces to achieve the missions that are most important for our nation’s security. This strategy would also leave U.S. alliances and partnerships far stronger than they have been in decades. In the process, it would set conditions for restoring and maintaining deterrence across theaters for decades to come. And it would do so without sending America’s sons and daughters to fight unnecessary wars or bankrupting future generations of Americans.

Prioritization is never easy, but it is the task we must undertake today. Only by embracing that difficult task, as conservatives did in decades past, can we ensure the strong national defense that all Americans deserve and require to be safe, free, and prosperous.

Kevin Roberts, PhD, President
The Heritage Foundation
July 2024

The Prioritization Imperative

The United States emerged from the Cold War with the world’s most powerful military by a wide margin. U.S. forces enjoyed clear if not decisive advantages in key theaters and were expected to be able to defeat multiple adversaries simultaneously. But that is no longer the case. After decades of war and mismanagement, U.S. forces are stretched thin around the world, with many of them suffering from readiness challenges—including recruiting shortfalls, weapons shortages, and maintenance backlogs—and delayed modernization. As a result, the American military no longer enjoys many of the advantages that it enjoyed when the Soviet Union fell.REF

Today, for instance, the United States has a very strong interest in preventing China from dominating the Indo-Pacific, most urgently by deterring a Chinese invasion of Taiwan. But it is no longer clear that the United States will be able to deter Beijing. Worse still, if deterrence fails, there is a real chance that China will be able to defeat the United States in a war over Taiwan.

At the same time, the American military is sized to fight and win only one major war at a time. Consequently, if U.S. forces went to war in one theater, adversaries may use this as an opportunity for aggression in other theaters, whether in coordination with one another or on their own initiative. This would be less troubling if allies and partners could reliably fill in for U.S. forces, but decades of free-riding have left many of them unable to do so. As a result, if the United States was drawn into a major conflict, there would be significant risk of cascading escalation across theaters, potentially culminating in a third world war.

The American homeland is also increasingly vulnerable. As tensions rise abroad, there is increased risk of enemy nuclear use against the United States. The risk of enemy non-nuclear missile strikes or destructive cyberattacks against U.S. targets is also rising. Meanwhile, America’s borders face overwhelming flows of migrants and narcotics, including foreign nationals who could threaten U.S. national security and drugs that are responsible for tens of thousands of American deaths per year.

These are difficult times, to be sure—but the future is not yet written. The United States has overcome periods of great danger before, and it can do so again. But this will require prioritizing. America’s military cannot be everywhere at once. Therefore, the United States must focus U.S. forces where they are needed most, consistent with America’s interests, while strengthening allied and partner burden-sharing in other areas.

In practical terms, this is a proposal for the United States to focus U.S. forces on defending the American homeland and denying China’s imperial ambitions, most urgently by deterring Beijing from invading Taiwan and offering the President credible options if deterrence fails. These are the most important missions that America’s military must be able to accomplish to preserve Americans’ security, prosperity, and freedom. Consequently, they must be America’s top defense priorities.

This does not mean that the United States should abandon other theaters or allies, however. Instead, the United States must find ways to defend U.S. interests in those theaters without jeopardizing the ability of U.S. forces to defend the U.S. homeland and deny China’s imperial ambitions, which are higher priorities. To that end, Washington should empower allies and partners to lead efforts to defend against Russia, Iran, and North Korea with critical but more limited U.S. support. This will allow us to avoid cascading escalation by ensuring that allies and partners can deter opportunistic aggression even if key U.S. forces are drawn away from their respective regions, for instance, to deter or defeat Chinese aggression. And it will leave U.S. alliances and partnerships far stronger than they have been at any time in the post–Cold War era.

Prioritization is always difficult—but there are no better options. Even if the United States spent far more on defense—which is unlikely for the foreseeable future—it would take years to rebuild America’s military so that it could win multiple major wars simultaneously, thereby reliably deterring all U.S. adversaries at once. In the meantime, prioritization would remain necessary. Nor are artificial intelligence, unmanned systems, or other emerging technologies likely to be panaceas any time soon.

Another option would be for the United States to try to sequence threats—for instance, by defeating Russian aggression in Ukraine before shifting focus to other theaters. But this strategy fails in the face of simultaneous crises, which is what we already see today on a relatively small scale with Europe and the Middle East at war and the Indo-Pacific potentially not far behind. Alternatively, Washington might simply try to bluff—to convince adversaries that it can defeat all of them at once even if it cannot. But the limits of U.S. military power are increasingly evident. As a result, adversaries are increasingly likely to call our bluff, and if they do, this strategy will collapse like the proverbial house of cards.

This is a period of great danger but also of great opportunity. It is only natural that the strategic environment has shifted since the end of the Cold War, and U.S. policy should shift with it. Change, however, does not mean defeat. If the United States adopts a strategy along the lines described in this paper, it will not only be able to reverse the erosion of America’s homeland defenses and prevent China from achieving hegemony in the Indo-Pacific. It will also be able to revitalize U.S. alliances and partnerships, thereby ensuring that we are collectively able to deter aggression in all of the world’s key regions. In this way, the United States can set conditions for lasting stability around the world on terms that ensure Americans’ security, prosperity, and freedom not just for the remainder of this decade, but for decades to come.

The Logic of American Defense Strategy

The highest purpose of American government—and the U.S. military specifically—is to preserve and advance Americans’ security, prosperity, and freedom.REF Absent physical security, the United States cannot exist as a successful, functioning state. Prosperity is a requirement for the success of our republic as well, not least because all Americans should be able to pursue their dreams and live dignified lives. Finally, freedom is a core part of what makes the United States unique. Defending that freedom is as important as any other task facing our nation’s military.

Homeland Defense. Protecting Americans’ security, prosperity, and freedom begins with defending the U.S. homeland. There is no more consequential threat to the U.S. homeland than large-scale nuclear attack, so America must modernize and expand U.S. nuclear forces to deter Russia,REF China,REF and North Korea.REF This is vital not just to keep them from laying waste to American cities, but also to prevent them from using threats to the U.S. homeland to compel us to abandon our allies and interests abroad.REF A strong nuclear deterrent is also important to deter China, Russia, or others from using non-nuclear weapons of mass destruction (WMD) against U.S. territory.REF

In addition, America requires stronger defenses against a variety of missile threats. Existing technologies may be unable to defeat large missile barrages in a cost-effective manner, but even the ability to defeat smaller salvos reliably will help to deter adversaries from launching them in the first place and limit damage if deterrence fails. America must also be vigilant in preventing China or other enemies from positioning military forces in the Western Hemisphere that could significantly increase the missile threat to the homeland, not to mention potential threats to regional trade and other interests.REF At the same time, the United States must field more robust defenses, including cyber and other offensive options, against destructive cyberattacks. This is vital for protecting infrastructure that is critical not just for the lives and livelihoods of millions of Americans, but also for our ability to mobilize forces and project power.REF

Finally, the United States is in the midst of historically high levels of illegal immigration. This both endangers the lives and livelihoods of ordinary Americans and poses significant risks to our national security. In recent years, for instance, U.S. Customs and Border Protection has encountered tens of thousands of Chinese nationals along the U.S. southern border in a sharp uptick from prior years.REF Congressional officials are rightly concerned about these individuals’ potential ties to the Chinese government and the possibility that they may be in the United States for purposes of espionage, sabotage, or related activities.REF At the same time, tens of thousands of Americans die annually from drug overdoses caused by the flow of fentanyl and other narcotics over the U.S. southern border.REF As leading Members of Congress from both sides have assessed, this is a national security threat—and the Department of Defense (DOD) has a role to play.REF

Indeed, for most of America’s history, the U.S. military has played a vital role in defending our nation’s frontiers, from manning coastal defenses and forts to prosecuting campaigns against revolutionaries and bandits moving north from Mexico.REF The U.S. military has also operated south of the border—for example, through direct action and counternarcotics training with regional partners.REF While border control is primarily a law enforcement and homeland security mission, DOD must be prepared to support those efforts, including by providing forces for broad-area surveillance, maritime interdiction, military engineering, counternarcotics capacity-building, intelligence collection, and direct action against high-value targets in the Americas.REF

Balancing Power in Key Regions. Defending the U.S. homeland is vital, but it will not be enough to protect Americans’ security, prosperity, and freedom in the 21st century. Even if the United States erected the most formidable homeland defenses, if a foreign rival took control of a key region of the world, it could grow powerful enough to be a severe threat to America’s most vital interests.REF

“Key region,” in this usage, refers to any region whose conquest by a foreign rival would allow that rival to deny U.S. access to markets upon which our society depends, grow its power to the point where it might realistically contend for global hegemony, or both.REF Today, these regions are the Indo-Pacific, Europe, and the Middle East in that order. Of those regions, only one is home to a rival of the United States that might be able to achieve regional hegemony: China in the Indo-Pacific.

Denying China’s imperial ambitions, then, must be America’s top priority outside of homeland defense even as the United States confronts other threats using a combination of U.S. forces that are not required for—and do not need to be divested to free resources forREF— defending the U.S. homeland or deterring China and stronger burden-sharing with allies and partners.REF Prioritization will be especially critical for the foreseeable future because the U.S. military is sized to fight and win only one major war at a time, and this is not likely to change any time soon.

The Indo-Pacific. China seeks hegemony in the Indo-Pacific.REF If it succeeds, it will be able to regulate U.S. access to many of the world’s most vital markets. As the Biden Administration has acknowledged, the Indo-Pacific “accounts for 60 percent of global GDP as well as two-thirds of global economic growth” and “is an essential driver of America’s future security and prosperity.”REF This echoes previous findings by the Trump Administration, which reported that “[n]ine of the world’s 10 busiest seaports are in the region, and 60 percent of global maritime trade transits through Asia, with roughly one-third of global shipping passing through the South China Sea alone.”REF

But Beijing’s ambitions go beyond the Indo-Pacific: It seeks global preeminence.REF In 1956, Mao Zedong told a Chinese Communist Party (CCP) audience that “to overtake the United States is not only possible, but absolutely necessary and obligatory.”REF More recently, Xi Jinping has called on the CCP to “concentrate our efforts on bettering our own affairs, continually broadening our comprehensive national power…and laying the foundation for a future where we will win the initiative and have the dominant position.”REF

Success in achieving this agenda would position Beijing to exercise all of the prerogatives of a new, hostile global hegemon. Not only would China be able to strangle America’s economy even as its own grew more powerful; it also could use its market power to compel private companies to spy on and blackmail Americans and restrict our ability to work, travel, and do business—to live freely on our own terms. A new, hostile global hegemon could raise military forces to enforce its global ambitions as well, from denying U.S. access to certain global commons to deploying its own forces in the Western Hemisphere.

Washington must therefore dedicate itself to denying China’s imperial ambitions—starting in the Indo-Pacific.REF This is vital not just to prevent Beijing from cordoning Americans out of Asian markets and maritime routes, but also to deny Beijing’s global ambitions. China will be unable to project domineering power globally until it has military supremacy in the Indo-Pacific. China must also control a larger share of Asia’s resources before it can dominate the world. In addition, confronting China in the Indo-Pacific will limit Beijing’s ability to equip proxies in other regions by forcing Chinese leaders to focus more of their nation’s resources on shoring up China’s position in the Indo-Pacific. Conversely, if China achieves hegemony in the Indo-Pacific, it will be able to invest far larger shares of its diplomatic, economic, and military capital in supporting proxies in other regions.

Military power will be key in any effort to deny China’s imperial ambitions. If Beijing can use force to dominate its neighbors, it is very likely to do so, and they will have little choice but to acquiesce.REF This would effectively cede regional hegemony to Beijing. The U.S. military must therefore deny Beijing’s ability to achieve such dominance. Crucially, this requires U.S. forces to focus first and foremost on preparing for large-scale war. If they can reliably defeat Chinese forces in this scenario, they will be far better positioned to prevent Beijing from conquering its neighbors—ideally by deterring Beijing from trying—or otherwise imposing its will on them. They will also be more able to deter or mitigate Beijing’s use of military coercion short of war against its neighbors. Conversely, if U.S. forces focus on countering Chinese military coercion short of war at the expense of America’s ability to defeat China in a large-scale war, Beijing will have an incentive to escalate to higher levels, at which point the United States will struggle to prevent China from using force to dominate others in the region.

Preparing for large-scale war in the Indo-Pacific is most urgent in the case of Taiwan. According to U.S. officials, Xi Jinping has directed China’s military to be ready to invade Taiwan by 2027, and the People’s Liberation Army (PLA) is on track to achieve that goal.REF At the same time, Xi may not wait until 2027 to order an invasion. As Admiral Samuel Paparo, Commander of U.S. Indo-Pacific Command, testified recently, “I think they are working to be ready every day, and they could go, and we have got to be constantly vigilant.”REF

Vigilance is essential because Taiwan’s fall would harm American interests in several ways. First, it would cede key military terrain to Beijing.REF Having broken through the First Island Chain, China would be better positioned to project military power against Japan, South Korea, and the Philippines as well as U.S. territories in the Western Pacific like Guam and the Northern Marianas. Beijing would also be able to reallocate forces previously focused on a Taiwan contingency toward these U.S. allies and territories as well as other targets in the South China Sea and beyond.

Taiwan’s fall would also weaken America’s ability to rally others to resist Chinese coercion.REF As it stands, many in the region believe the United States has committed itself to defending Taiwan—even more so because President Biden has done so explicitly on at last four occasions. If the United States shows itself unwilling or unable to fulfill that perceived commitment, others in the region may doubt America’s willingness or ability to defend them. They are likely to stand firm against Chinese demands only with support from the United States because none of them are powerful enough to resist China on their own. If they believe that support will not be forthcoming, then they are more likely to see resistance as costly and futile and, as a result, accede to Beijing’s demands.

Finally, Taiwan’s fall might enable Beijing to seize control of Taiwan’s semiconductor industry. This would significantly improve China’s ability to use economic coercion against the United States and others not just in the Indo-Pacific, but also in Europe, the Middle East, and other regions. This would only further complicate U.S. efforts to build a coalition to resist China’s imperial ambitions.REF

Despite Taiwan’s importance to American interests, however, it is not clear that U.S. forces will be able to deter or defeat a Chinese invasion of Taiwan in the next several years.REF As the RAND Corporation has found, America’s current approach in the Indo-Pacific “leave[s] open the possibility of a rapid victory by China.”REF This is partly due to Chinese forces’ proximity and numerical advantages, especially at sea and in the air, but China’s military is also increasingly capable and taking steps to offset whatever advantages the United States might bring to a Taiwan contingency, including by eroding America’s ability to obtain warning prior to an invasion.REF

To deter Beijing, Washington must therefore surge investments in America’s deterrent posture in the Western Pacific. Particular attention should be given to strengthening the ability of U.S. forces to deny a Chinese fait accompli—an attempt by Beijing to seize control of Taiwan rapidly before the United States and its allies can respond effectively. To that end, the United States must intensify intelligence-gathering on Chinese forces and stockpile weapons required for a Taiwan contingency. It must also harden and disperse U.S. operating locations in the First and Second Island Chains, including by securing and improving U.S. military access in Japan, the Philippines, and Australia and accelerating military construction on Guam and the Northern Marianas. DOD must take full advantage of this new force posture as soon as possible by accelerating the development and implementation of concepts for distributed operations.

At the same time, DOD must shift certain forces from other theaters to the Indo-Pacific with a particular focus on submarines, air and missile defenses, and other assets that must be in position very early in a conflict to deny a Chinese fait accompli and will be difficult to swing quickly to the Indo-Pacific after an invasion begins or U.S. forces learn that an invasion is imminent. It must also preserve as much strike capacity as possible, especially by breaking through naval maintenance backlogs. In addition, DOD should accelerate adoption of emerging capabilities—such as certain unmanned systems—that could make a significant difference on the battlefield in the next few years. Finally, DOD must update U.S. nuclear planning to account for possible theater nuclear escalation in a Taiwan contingency.

The United States must accelerate efforts to strengthen Taiwan’s defenses as well. If deterrence fails, China will seek to hold off U.S. forces long enough for Chinese forces to land on Taiwan, establish lodgments, seize key terrain, and displace Taiwan’s government. At that point, Beijing will have achieved a fait accompli. To prevent this, U.S. and allied forces must be able to strike Chinese landing forces from the outset of a conflict. However, U.S. forces will likely have difficulty doing so at scale in the initial period of war as they fight through China’s layered defenses around Taiwan. Therefore, our collective ability to deny a Chinese fait accompli hinges in significant measure on Taiwan’s own ability to delay, degrade, and destroy Chinese airborne, air assault, and amphibious forces.

To do this, Taiwan’s military needs large numbers of asymmetric defense capabilities, including mobile anti-ship missiles, naval mines, and mobile air and missile defenses, as well as long-range artillery, anti-armor weapons, and other capabilities for Taiwanese ground forces that will likely be called on to defeat any Chinese forces that do make landfall. However, Taiwan still does not have many of these weapons. Moreover, even after those weapons arrive on the island, Taiwanese forces will still require time to absorb and field them.

The United States must therefore accelerate delivery of these asymmetric defense capabilities, along with associated training and other support, to Taiwan to the greatest extent possible. In particular, this will require prioritizing efforts to arm Taiwan over efforts to arm Ukraine, which requires many of the same systems that Taiwan needs for its defense.REF In cases where the United States has enough systems for both, it may still be able to provide those weapons to Ukraine. Where the United States lacks the ability to resource both sets of requirements fully and at the same time, this approach will ensure that Taiwan gets what it needs as quickly as possible, consistent with American interests. Finally, even as the United States accelerates efforts to arm Taiwan, it must also work closely with Taipei to ensure that Taiwan is doing everything possible to strengthen its defenses, to include raising defense spending to a level commensurate with the existential threat it faces, prioritizing the acquisition of asymmetric defense capabilities, and accelerating necessary defense reforms. It will be hard enough to deter or defeat a Chinese invasion: If Taiwan does not do its part, it could become impossible.REF

The United States should also sustain efforts to help other regional allies, including Japan, Australia, and the Philippines, to strengthen their defenses. In some cases, this will contribute directly to the ability of U.S. and allied forces to deter or defeat a Chinese invasion of Taiwan. Japanese and Australian forces, for instance, could make a significant difference in such a contest, and both countries share America’s interest in preventing China from breaking through the First Island Chain. In other cases, strengthening regional militaries might not contribute directly to Taiwan’s defense but could complicate Chinese planning—for example, by compelling Beijing to split forces between theater military commands or operating areas. If Indian forces, for instance, were equipped and positioned to seize disputed territory in the event China focused military resources on a Taiwan contingency, Beijing might be less likely to concentrate as many forces on a Taiwan campaign as it would otherwise.

These investments in U.S. and allied deterrent postures in the Indo-Pacific will not only maximize our ability to deter or defeat a Chinese invasion of Taiwan. They will also maximize options available to the United States and its allies to support Taiwan in the event of a Chinese blockade, which would be part of a broader invasion operation and, on its own, poses less of a threat then a direct amphibious assault.

At the same time, investments in America’s deterrent posture in the Indo-Pacific are necessary to position the United States to deter further Chinese aggression if Taiwan falls. For even if Taiwan does fall, Beijing’s appetite is not likely to be satiated, and the United States will still have a most compelling interest in denying China further progress toward regional hegemony—but it will only be harder and more costly to do so. Indeed, even if other countries in the region strengthen their own defenses in response to China’s successful invasion of Taiwan,REF they still will not be powerful enough to withstand China on their own. Consequently, the United States will still be required to provide critical military support, up to and including direct intervention, to prevent Beijing from dominating those countries—but it will be forced to do so from a weaker position, having allowed Beijing to break through the First Island Chain.

To be sure, China faces its own problems. China’s economic growth is slowing, and the country faces serious headwinds over the long term.REF But short of outright collapse, which appears unlikely in the near term,REF China will remain a formidable adversary. U.S. policymakers must therefore stay vigilant, especially during this decade when China is best positioned to advance its imperial ambitions, with economic and demographic challenges not yet fully arrived, and Chinese military power at or near its peak relative to the United States and Taiwan as a result of China’s defense investments and delays in U.S. and Taiwanese military preparations.

North Korea also threatens U.S. interests but not nearly to the same extent as China does. Pyongyang simply is not powerful enough to contend for regional hegemony. Even so, in addition to protecting the U.S. homeland against North Korean nuclear attack, America has a strong interest in deterring Pyongyang from using force against U.S. allies South Korea and Japan. This is partly because the United States has treaty obligations to defend both allies. Failure to do so would complicate efforts to rally other Asian nations to resist Chinese demands. It would also damage U.S. relations with South Korea and Japan, both of which can be critical force multipliers. Not only do they support U.S. goals of maintaining a free and open Indo-Pacific, but they also provide important access for U.S. military forces. Especially in the case of Japan, this is vital to deterring Beijing and denying China’s imperial ambitions.

But the United States must uphold its treaty obligations to South Korea and Japan while maintaining its ability to defend the U.S. homeland and deter China. In the case of South Korea, given constraints on the U.S. military, the best way to do this is by empowering South Korea to lead efforts to deter or defeat a North Korean invasion.REF Washington and Seoul have long worked toward this goal, most recently under the Conditions-Based Operational Control (OPCON) Transition Plan (COTP), and have made substantial progress. In fact, with its formidable military and expansive defense industry, South Korea is now one of America’s strongest allies.

The United States and South Korea should rededicate themselves to achieving that transition as quickly as possible. By doing so, the United States and South Korea can substantially improve their collective ability to deter North Korea. They can also ensure that South Korea is able to lead its own defense even if the United States is simultaneously drawn into a conflict with China over Taiwan. This is crucial not just for U.S. interests, but also for South Korea’s because America’s ability to deter or win a war over Taiwan will be essential to denying China the ability to control South Korea’s sea lines of communication or otherwise impose its will on South Korea after defeating the United States.REF Consistent with U.S. treaty obligations, the United States will still play a critical role in South Korea’s defense even as South Korea shifts into a leading role, including by providing conventional forces that are not required to defend the U.S. homeland or deter China and do not need to be divested in service of those priorities.

In addition, given the importance of its alliances with South Korea and Japan, the United States has a strong interest in credibly and effectively deterring North Korea from using nuclear weapons or other WMD against these allies. To that end, the United States will maintain and strengthen its extended nuclear deterrent, including by expanding and diversifying the U.S. nuclear arsenal and enhancing nuclear coordination with South Korea through the bilateral Nuclear Consultative Group. America can also bolster the credibility of its extended deterrent by strengthening U.S. homeland missile defenses. Finally, the United States, South Korea, and Japan must field more robust and cost-effective theater missile defensesREF and evaluate other options to ensure a credible defense of both allies, especially if it becomes clear that North Korea will be able to outpace and overwhelm U.S. homeland missile defenses.REF

Europe. Europe is also important for American interests but less so than the Indo-Pacific. If a foreign rival were able to dominate Europe, it could regulate U.S. access to that region’s very important markets. It might also be powerful enough to make a play for global hegemony. But Europe’s share of the global economy is shrinking.REF Moreover, no country has a credible path to regional hegemony.

Most notably, Russia seeks a sphere of influence in Eastern Europe and potentially beyond.REF But gains in Ukraine notwithstanding, Russia has struggled to turn that vision into reality and lacks the economic or military power to aim far beyond its periphery for the foreseeable future. Russia’s gross domestic product (GDP) is approximately 10 times smaller than that of our allies in Europe and Canada,REF and although Moscow has generated significant combat power in Ukraine, as long as this economic imbalance persists, Russia will be unable to generate and sustain the military power required to seize control of large portions of Europe as the Soviets did or otherwise impose its will on Europe in the face of determined resistance.

This is not to say that Russia does not pose a threat. To the contrary, Moscow has shown that it is willing to use force in certain contexts, and Russia’s military still poses a serious threat to countries on Russia’s borders. This is evident in Ukraine, but it also applies to North Atlantic Treaty Organization (NATO) allies on the eastern front, including Poland, Lithuania, Latvia, Estonia, and Finland. Because of Russia’s ongoing operations in Ukraine, the Kremlin is not currently able to concentrate forces on those allies, but as Russia regenerates forces, and especially if the war in Ukraine winds down, Moscow will likely shift units back toward NATO’s borders. At that point—which could occur in just a few years or possibly even sooner—NATO will be confronted once more with the threat of a Russian fait accompli. If NATO were unable to deter or defeat such an operation, not only would further war in Europe become more likely, but Russia may also be able to use military force to significantly weaken NATO itself.REF

This matters for the United States because America has an interest in NATO’s remaining an effective military alliance. For decades, NATO has served as a bulwark against Soviet and then Russian aggression. It also has inhibited the sort of European militarization that preceded two world wars in the 20th century. In these regards, it has been an effective mechanism for maintaining a favorable balance of power in Europe, and the United States likewise has an interest in this remaining the case.

However, NATO has weakened considerably in recent decades as a result of allied free-riding. This is evident in the collapse of NATO allies’ defense spending after the Cold War. It is further evident in many allies’ slow progress toward spending (or outright failure to spend) 2 percent of GDP on defense despite first agreeing to do so in 2006REF and the NATO Supreme Allied Commander’s public acknowledgement that 2 percent is no longer an adequate minimum.REF Many allies also have struggled to bolster their own troop presence in NATO’s eastREF and provide critical military aid to Ukraine.REF The United States must therefore work closely with its allies to strengthen NATO so that the Alliance can do what is required to defend Europe even as U.S. forces focus first on defending the U.S. homeland and denying China’s imperial ambitions.

To that end, the United States must lead the adoption of a new distribution of labor among NATO allies. Specifically, because the United States must focus tightly on homeland defense and urgently strengthening deterrence against China, our NATO allies must take primary responsibility for Europe’s conventional defense.REF That includes providing most if not all of the conventional forces required to defeat Russian aggression against NATO, including in the air and seas near Europe, consistent with NATO’s embrace of deterrence by denial.REF At the same time, America can still provide its extended nuclear deterrent as well as conventional forces that are not required to defend the U.S. homeland or deter China and do not need to be divested in service of those higher priorities.REF Under this arrangement, consistent with U.S. treaty obligations, including Article 5 of the North Atlantic Treaty,REF the United States will still play a vital role in NATO. At the same time, NATO will be far better positioned to deter or defeat Russian aggression even if U.S. forces are drawn into a conflict elsewhere.

To facilitate adoption of this new distribution of labor, DOD, in coordination with relevant U.S. agencies, should identify for NATO allies which U.S. forces are assigned to NATO’s regional defense plans—especially the defense of the Baltics, Poland, or Finland—but also are required for a Taiwan contingency. These are the forces that our allies most urgently need to field on their own. Next, having identified U.S. forces in need of replacement by allies, Washington should support allies’ efforts to field those forces as quickly as possible—including by supporting measures to strengthen allied defense industries as appropriateREF—and set clear timelines for the transfer of relevant U.S. forces from Europe to incentivize allied investments. Although the precise forces affected by this transition will be classified, they will likely include submarines and surface combatants; heavy bombers; fighter, electronic attack, maritime patrol, and airborne early warning and control (AEW&C) aircraft; air and missile defenses; certain ground-based long-range fires; critical munitions for air, naval, and ground platforms; and critical enablers, such as airlift, sealift, and intelligence, surveillance, and reconnaissance (ISR) assets.REF

As NATO allies take primary responsibility for Europe’s conventional defense, they must also take the lead in providing military aid for Ukraine.REF Moscow has reason to keep fighting as long as it believes it can still achieve its objectives in Ukraine.REF Ukraine’s task is to persuade Russia that it cannot prevail and therefore would be better off if it ended the war. The best way for Ukraine to do this is by dealing Russia a series of military defeats that leave no doubt in Russian leaders’ minds that their military can go no farther and that more fighting will only result in additional costs and few if any benefits. But Ukraine’s forces need more weapons to mount such a defense, and Ukraine cannot yet produce them on its own. Meanwhile, the United States has limited inventories and production capacity.REF Consequently, for Ukraine to defend itself effectively, Europe must supply the bulk of the weapons with the United States providing more limited support.REF

Finally, NATO has spoken in recent years about doing more in the Indo-PacificREF—but this is folly. NATO’s priority is and must remain Europe’s defense. Moreover, even if NATO allies wish to help the United States in the Indo-Pacific, the best way for them to do so (with very rare exceptions) is not by directing their own attention and resources to that theater at Europe’s expense, but by taking primary responsibility for Europe’s conventional defense while the United States focuses its own forces on the China threat. The United States should urge NATO allies to act accordingly.

The Middle East. The Middle East lacks the market power of the Indo-Pacific or Europe.REF As a result, even if a rival gains control of the region, it will have difficulty contending for global hegemony. However, a regional hegemon would still threaten U.S. interests. Not only could it restrict Gulf oil flows, thereby driving up global energy prices and imposing costs on Americans even if the United States boosts its own production, but it also could also disrupt or block shipping in the region, again imposing costs on Americans. The United States therefore has an interest in preventing a rival from dominating the Middle East. Fortunately, Russia is in no position to do so. Nor can China do so unless it first achieves hegemony in the Indo-Pacific. That leaves Iran.

Iran is a formidable adversary, but it is not yet positioned to dominate the region. To do so, it would need to conquer its neighbors or coerce them into submission.REF However, Iran’s ability to mount large-scale ground operations is very limited, so large-scale conquest is not an option.REF At the same time, Iran regularly uses its powerful missile, drone, and proxy forces to coerce its neighbors, as seen in its high-profile barrage against Israel in April 2024.REF But that has not yet convinced Israel, Saudi Arabia, Jordan, and others in the region to submit to Tehran’s will. Instead, most of Iran’s neighbors are strengthening their defenses, which suggests they intend to keep resisting.REF

America’s task is to keep it that way and, in the process, block Iran’s path to regional hegemony and strengthen defenses against all forms of Iranian aggression. This starts with strongly supporting Israel’s defense by supplying weapons, intelligence, and other aid that Israel requires to defend itself and clearly advocating Israel’s right to do just that. This should be a top priority given America’s unique and long-standing relationship with Israel, but it also directly aids U.S. efforts to counter Iran.

It does this first by enabling Israel to degrade Iran’s ability to project power in the region, including by disrupting Iran’s nuclear program. At the same time, U.S. support for Israel helps to strengthen defense cooperation between Israel and the Gulf States, building on the Abraham Accords and other initiatives. These states are far more likely to cooperate with Israel if they view it as a strong military partner, and the United States has a strong interest in their doing so, especially in terms of air and missile defense, maritime security, counterterrorism, and related activities. This helps to protect U.S. interests, such as safeguarding Gulf oil flows and regional shipping. It also reduces requirements for U.S. forcesREF and may foster cycles of closer cooperation.REF

Other nations can contribute as well. The United States is far less dependent on Gulf oil and regional shipping than many in Europe and the Indo-Pacific are. Given this disparity of interests, Washington can and must rely more on those nations to defend these shared interests, as it has in the past.REF As an example, European navies—not the U.S. Navy—should be primarily responsible for defending European shipping.REF Indo-Pacific allies should also send escorts, though not at the expense of our collective ability to deter China. Finally, the United States has an interest in forcing China to protect its own commercial interests in the Red Sea, not least to force China to expend military resources where it may otherwise prefer not to expend them. Under no foreseeable circumstances should U.S. forces do anything to ease this dilemma for Beijing.

U.S. forces will still have a role to play. Most urgently, the United States must retain—or, as needed, develop—its ability to destroy Iran’s nuclear facilities. U.S. forces must also be able to act decisively in the rare cases where a focused, limited intervention is needed—for example, if Israel’s survival was in doubt.REF Finally, the United States must always be able to impose severe costs on Iran’s leaders. They must never be allowed to think they can harm Americans or America’s interests with impunity.

But the United States must be able to do these things without detracting from U.S. force posture in the Indo-Pacific. This is important not only so that the United States can continue to deter China even as it responds to Iranian aggression, but also because it lends credibility to U.S. threats against Iran by eliminating any hope Tehran might have had that the United States will not respond forcefully to Iranian aggression for fear of inviting Chinese aggression in the Indo-Pacific. Achieving this goal, however, will require ensuring that operational plans related to Israel’s defense and select other Middle East contingencies rely primarily if not exclusively on weapons that are not required for Taiwan’s defense, such as fourth-generation aircraft and shorter-range air-to-ground weapons.

This approach will become even more important if Iran obtains nuclear weapons. As it stands, Iran is a threshold state, which means that it is likely capable of producing nuclear warheads in a relatively short period of time if it chooses to do so. After that, it would still need to upload warheads onto missiles or other delivery vehicles. But if it has gone so far as to produce warheads, there is every reason to expect that it will be able and willing to go this final mile and field an initial, modest nuclear force. Even a modest nuclear force of half a dozen nuclear weapons could embolden Tehran, however, if it believes that its nuclear forces will help to shield it from reprisal.REF

In this case, the task for the United States will be as it was before: to strengthen deterrence against all forms of Iranian aggression. It will thus become even more important for the United States to maintain strong support for Israel’s defense and enable integration between Israel and its neighbors, especially for air and missile defense operations, as part of a broader effort to weaken Iran’s ability to engage in unconventional, conventional, and now nuclear coercion. At the same time, maintaining America’s ability to hold Iranian nuclear facilities at risk may provide options for escalation management. As before, however, the United States must be able to engage those or other regional targets in a limited but decisive manner, relying primarily if not exclusively on forces that are not required for a Taiwan contingency.

Finally, the United States must prevent al-Qaeda, ISIS, and other Islamist terrorists from using Middle East safe havens to attack the U.S. homeland. As the 2018 National Defense Strategy (NDS) directed, however, it must do so on a resource-sustainable basis, especially by targeting terrorists that have the ability to strike the U.S. homeland and relying more on standoff capabilities and local partners.REF European allies like France can also do more, including in North Africa, not least because terrorists operating in these regions pose a greater threat to Europe than they do to the United States.

Washington will likely still need to deploy special operations and other forces to neutralize terrorists at times, but it must not do so on an open-ended basis, which is a recipe for endless war.REF Nor should it leave U.S. forces engaged in counterterrorism operations dangerously exposed to attacks by Iran or its proxies.REF That is an abrogation of U.S. leaders’ responsibility to protect U.S. servicemembers. It also creates opportunities for Tehran to impose costs on Washington and draw us into a regional war that we might otherwise prefer to avoid.REF And it forces the United States to send air and missile defenses to the Middle East at the expense of the U.S. homeland and Indo-Pacific.REF

Other Missions. U.S. forces often engage in activities that are unrelated or only tangentially related to homeland defense or power-balancing in key regions, such as nation-building, humanitarian aid, disaster relief, and peacekeeping. As important as many of these missions may be, they are ultimately less important for ensuring Americans’ security, prosperity, and freedom than defending the U.S. homeland and balancing power in key regions are. The latter must therefore take precedence. Sometimes this will mean forgoing missions altogether. In other cases, Washington will need to rely more on other nations.

The Prioritization Imperative

Prioritization would be less necessary if U.S. forces could deal with the myriad threats facing our nation all at once. But that is not the case. To the contrary, the ability of U.S. forces to confront multiple threats simultaneously is limited, and there is no easy way to solve this problem any time soon. Consequently, if the United States is to achieve its most important defense objectives—defending the homeland and denying China’s imperial ambitions—it must prioritize. By doing so, it can not only safeguard America’s most vital interests, but also strengthen U.S. alliances and partnerships around the world and, in the process, set conditions for lasting peace in each of the world’s key regions on terms favorable to the United States.

This is especially important today because years of American military overextension have resulted in a situation in which security equilibria in Europe, the Middle East, and the Indo-Pacific all depend on America’s ability to intervene decisively to deter or defeat aggression. But the U.S. military is sized to fight and win only one major war at a time, so if America goes to war in any single theater, there will be significant risk of opportunistic aggression in other theaters. As a result, if U.S. allies and partners are not ready to deter such opportunism, then a single conflict might quickly evolve into a third world war.

The Simultaneity Problem. The 2018 and 2022 NDSs make clear that the U.S. military is not sized to win two major wars at the same time or in close sequence.REF That is because U.S. forces require many of the same platforms, munitions, and enablers for large-scale conflicts against China, Russia, Iran, and North Korea. In many cases, however, it is not clear that the United States has enough of these capabilities to defeat China alone, to say nothing of multiple adversaries in short order, especially in the event of combat losses and the likelihood of higher-than-anticipated expenditure rates for critical munitions. This is the “simultaneity problem.”

To illustrate this problem, the following is a list of platforms, munitions, and enablers that are required to deter or defeat Chinese aggression but also are needed for one or more other contingencies. In many cases, it is already clear that the U.S. military lacks enough of these capabilities to reliably deter or prevail in a war against China.

• Submarines. U.S. attack submarines will play a critical role in degrading Chinese surface forces during a Taiwan contingency, especially in the initial period of war. They may also be assigned to trail Chinese submarines. But U.S. attack submarines will also be needed to counter Russia’s undersea forces, among other targets. Certain U.S. attack submarines may also be tasked with engaging Iranian naval forces and striking Iranian and North Korean ground targets.REF Yet because of maintenance backlogs, nearly a third of America’s attack submarines are unavailable.REF At the same time, it is unclear whether the United States has enough attack submarines forward in the Indo-Pacific to deny a Chinese fait accompli,REF and reports suggest that the U.S. Navy may be short of heavyweight torpedoes.REF
• Bombers. U.S. heavy bombers will be vital to defeating a Chinese invasion of Taiwan, but they will also be required to be available to engage a variety of Russian, Iranian, and North Korean targets, including hard and deeply buried targets (HDBTs).REF Moreover, especially in the case of China and Russia contingencies, they would likely use many of the same standoff munitions, such as JASSM (Joint Air-to-Surface Standoff Missile) and JASSM-ER (JASSM-Extended Range).REF But recent analysis by the Center for Strategic and International Studies (CSIS) finds that the United States may lack enough bombers for a Taiwan contingency alone, and separate analysis shows that the U.S. military probably lacks sufficient standoff munitions to defeat a Chinese invasion.REF In addition, bomber capacity will only grow more limited in the event of nuclear escalation, at which point a certain number of B-2s and B-52s may be tasked with performing their nuclear missions, thereby further reducing the number of bombers available for conventional operations.
• Fighter Aircraft. Fourth-generation-plus and fifth-generation aircraft will play a significant role in degrading Chinese air forces in a war over Taiwan and, in some cases, striking Chinese ships and ground targets or providing electronic support. Many of the same aircraft will likely also be required to be available to engage Russian air, naval, and ground forces as well as Iranian and North Korean targets, such as air and missile defenses.REF Yet the CSIS’s recent analysis warns that the United States is likely to lose large numbers of fighter aircraft in a Taiwan conflict.REF Moreover, separate reports show that many of the munitions that U.S. fighters will likely use against Chinese and Russian targets, in particular—including AMRAAM (Advanced Medium-Range Air-to-Air Missile); AARGM-ER (Advanced Anti-Radiation Guided Missile–Extended Range); JASSM; JASSM-ER; and JSM (Joint Strike Missile)—are not available in sufficient numbers for a Taiwan fight alone.REF Other air-launched weapons, such as JATM (Joint Advanced Tactical Missile) and HACM (Hypersonic Attack Cruise Missile), are still in development or the early stages of production, and it will likely take years to produce them at sufficient levels for a Taiwan contingency, much less for multiple simultaneous conflicts.REF Further, as with bombers, U.S. fighter capacity will grow more limited in the event of nuclear escalation as certain units are tasked with supporting or delivering nuclear strikes.REF
• Air and Missile Defenses. Ground-based air and missile defenses will be vital for protecting U.S. and allied forces during a Taiwan contingency. As it stands, however, the United States does not have enough THAAD (Terminal High Altitude Area Defense), Patriot, and related systems, including sea-based assets, along with the interceptors they employ, to protect U.S. forces on Guam or elsewhere in the Indo-Pacific.REF These systems are also in high demand in Europe, in the Middle East, and on the Korean Peninsula, and demand will increase if U.S. forces become more involved in those theaters.REF
• Long-Range Fires. The U.S. Army and Marine Corps will contribute significant ground-based long-range fires in the Western Pacific. Indeed, if the United States can position enough of these units forward in the First Island Chain prior to conflict—and supply them with adequate targeting data once hostilities begin—they could play a very important role in denying a Chinese fait accompli. But some of the long-range fires capabilities that would be used in a Taiwan campaign—such as LRHW (Long-Range Hypersonic Weapon); SMRF (Strategic Mid-Range Fires); TLAM (Tomahawk Land Attack Missile); HIMARS (High Mobility Artillery Rocket System); MLRS (Multiple Launch Rocket System); and PrSM (Precision Strike Missile)—would likely also be required for contingencies involving Russia, North Korea, or both.REF
• Airborne Early Warning and Control. AEW&C aircraft will be essential for monitoring and coordinating activity among U.S. air and naval forces in a Taiwan contingency. They will also play important roles in contingencies involving Russia, Iran, and North Korea.REF But America’s fleet of E-3 aircraft suffers from low availability, and the U.S. Air Force will not receive its first E-7 replacement until 2027.REF
• Intelligence, Surveillance, and Reconnaissance. Combatant commanders routinely testify that there are not enough intelligence, surveillance, and reconnaissance (ISR) assets to go around even in peacetime.REF The problem is particularly acute in the Indo-Pacific, where U.S. forces require additional ISR resources to generate targeting data on Chinese forces prior to war, and it will only grow worse in the event of conflict—and worse still in the event of nuclear escalation, with ISR resources likely to be reallocated in support of the nuclear mission.REF Airborne and space-based ISR assets will be in particularly high demand for any conflict.REF Depending on their trajectories, ISR satellites can provide coverage of targets in multiple theaters over the course of each orbit; in this sense, they are distinct from airborne assets, which are less able to swing quickly between theaters. Like airborne assets, however, ISR satellites are still subject to attrition. Forces damaged or destroyed by an adversary in one theater will no longer be available for use in the primary theater. Therefore, even with satellites, until the United States fields more resilient constellations for military use, scarcity can still become a factor.
• Airlift, Sealift, and Aerial Refueling. Airlift assets like the C-5, C-17, and C-130 will play crucial roles by delivering U.S. forces to and within theaters in the event of conflict involving China, Russia, Iran, and North Korea.REF However, General Jacqueline Van Ovost, Commander of U.S. Transportation Command, has testified that the United States will use all of its existing airlift capacity for a single large-scale combat operation, and these capacity constraints will likely worsen if the United States reassigns some number of C-17s and C-130s to combat patrols using palletized munitions.REF The United States also lacks adequate sealift capacity, and its fleet of tanker aircraft can support only one large-scale contingency at a time—at best—and that is all before attrition.REF Nuclear escalation will likely also result in U.S. tanker aircraft being assigned away from the conventional fight to support nuclear operations.REF
• Non-Strategic Nuclear Weapons. Since the Cold War, the United States has recognized that the best way to deter adversaries from using NSNWs at the theater level is to maintain America’s ability to respond proportionately. The problem is that the United States divested the vast majority of NSNWs after the Cold War.REF As a result, our existing inventories are now very small relative to those of China, Russia, and North Korea. Our NSNWs are also concentrated in the European theater and may not be able to swing quickly to other theaters. Moreover, even if they could, the United States would still have very limited numbers and types of NSNWs at its disposal relative to our adversaries. Consequently, if we find ourselves in a nuclear escalation sequence in any one theater, it will very likely trade against our ability to employ NSNWs in other theaters. This will weaken our ability to deter nuclear use or manage escalation in those other theaters, which in turn could significantly affect our ability to respond effectively if, for instance, Beijing initiated theater nuclear use for operational or coercive effect.

Given the above-described constraints, if the United States is to deter or defeat Chinese aggression, most urgently in the case of a Taiwan contingency, it must focus U.S. forces on doing just that. Conversely, if the United States goes to war against Russia, Iran, or North Korea, it will likely expend many of the capabilities required to deter or defeat Chinese aggression. At that point, not only will war in the Indo-Pacific be more likely, but there will also be a greater likelihood of Chinese forces defeating the United States in a war over Taiwan if we intervene.

Consequently, as long as deterring China is Washington’s priority and the U.S. military is sized to win only a single major war at a time, the United States will need to withhold forces required to defeat Chinese aggression from other theaters even if Russia, Iran, or North Korea initiates hostilities first. That is why it is so important for the United States to empower allies and partners in those theaters to lead efforts to defend against Russia, Iran, and North Korea with critical but more limited U.S. support, thereby ensuring our collective ability to deter or defeat those adversaries even if U.S. forces are withheld for or drawn into a conflict against China.

No Quick Solutions. There are several ways by which U.S. policymakers might try to solve the simultaneity problem, including by increasing U.S. defense spending, leveraging emerging technologies, sequencing, or bluffing—and some of them hold promise. None of them, however, is likely to pay off for at least several years. As a result, the United States must prioritize if it is to defend its most vital interests.

Increased Spending. The United States might try to solve the simultaneity problem by raising defense spending and growing the U.S. military. Some argue, for instance, that the United States should spend 5 percent of its GDP on defense, which would require spending hundreds of billions of dollars more per year.REF But there is little evidence that Americans will support the large and sustained defense spending increases that would be required to overcome the simultaneity problem. If anything, recent polling suggests the opposite.REF At the same time, fiscal constraints make such increases more difficult now than they were several decades ago.REF As a result, very significant defense spending increases appear unlikely for the foreseeable future. Moreover, even if these increases do occur, it will still take many years to produce all of the capabilities that U.S. forces will need to fight and win multiple major wars simultaneously.REF Meanwhile, the simultaneity problem will persist, as will the need to prioritize.

To be sure, DOD still can—and must—do more with the resources already available to it, including through base realignment and closure, contracting and civil service reform, cutting climate change programs that detract from warfighting readiness, shifting funds from research to procurement, and related initiatives.REF This approach would help to strengthen U.S. forces’ warfighting abilities under the existing topline and should be pursued aggressively. At the same time, prioritization will remain critical as long as savings are not forthcoming—for instance, due to political opposition—or prove insufficient to overcome the simultaneity problem.REF

Technological Offsets. There was a time when U.S. forces could rely on a technological advantage to offset quantitative limitations. In the late Cold War, for instance, DOD used the Second Offset Strategy to overcome Soviet forces’ quantitative advantage in Central Europe.REF But our technological advantage is no longer as clear in key scenarios. This is partly due to adversary improvements. It is also because of delays in U.S. military modernization.REF As a result, many of the military capabilities available to defend our nation are decades old with replacements long overdue.

DOD has tried to restore America’s military-technological advantage in recent years through the Third Offset Strategy, Replicator Initiative, and related efforts such as Hellscape,REF but progress has often been slow, and rivals’ own innovations may limit the magnitude or duration of any U.S. technological advantage.REF Likewise, even if DOD achieves lasting breakthroughs in certain areas—like using unmanned systems to find, fix, and engage targets—U.S. forces will still need to be postured appropriately, with adequate weapons stockpiles and other enablers, to fully exploit those advances.

For all of these reasons, U.S. policymakers should not bet on technological breakthroughs alone to solve the simultaneity problem in the near term. Instead, even as they pursue breakthroughs—prioritizing capabilities that are likely to make a significant difference in a Taiwan contingency in the next few years—they should hedge by investing in other aspects of U.S. conventional and nuclear forces, thereby complicating China’s military plans and maximizing the ability of U.S. forces to deter or prevail even if DOD’s most ambitious technology initiatives are late to need, not decisive, or decisive but only for a short period.

Sequencing. Another way to try to address the simultaneity problem is by “sequencing” threats, or dealing with one adversary—whether by defeating that adversary militarily, reconciling, or otherwise—before shifting attention to another.REF There is ample historical precedent for this approach,REF and Biden Administration officials indicate that they are pursuing a similar strategy.REF But sequencing works only if the United States has enough time to neutralize a threat in one theater before turning to another. This is a highly improbable outcome in today’s world with Israel fighting to defend itself, Russian forces regenerating and a protracted conflict underway in Ukraine, and Chinese aggression against Taiwan increasingly likely in the near future.REF

Timing might be less of a factor if the United States were confident of its ability to pivot quickly, but that is not the case, largely because of overlapping military requirements across theaters. This applies to U.S. forces, as described above, but it also applies to partners. The United States, for instance, has sent large quantities of weapons to Ukraine to defeat Russia’s invasion, including a significant number of weapons that U.S. or Taiwanese forces need to deter China such as HIMARS; ATACMS (Army Tactical Missile System); GMLRS (Guided Multiple Launch Rocket System); NASAMS (National Advanced Surface-to-Air Missile System); Patriots; Stingers; Javelins; and a variety of unmanned aerial vehicles (UAVs).REF But the U.S. military has only limited quantities of these weapons, and the U.S. defense industry has a limited ability to replenish them quickly. As a result, even if U.S. military aid were sufficient to allow Ukraine’s defenders to defeat Russia’s invasion, it would still significantly—and perhaps prohibitively—weaken America’s ability to turn quickly to deter China in the Indo-Pacific. The same dynamic might also incentivize Beijing to attack Taiwan sooner than it would have otherwise, thereby accelerating or precipitating the very conflict that Washington had sought to avoid through its strategy of sequencing.

Finally, the United States cannot ignore the possibility that adversaries will actively coordinate to stretch U.S. forces thin by escalating in multiple theaters at the same time. Simultaneous wars can occur without such coordination, purely as a form of opportunistic aggression. Indeed, opportunism may be more likely than outright coordination if adversaries lack trust or the ability to communicate securely with one another. But the time pressures facing U.S. forces will likely be worse in the event of coordination. In this case, sequencing will be impossible and, if attempted, could play into adversaries’ hands.

For instance, China is more likely to be able to achieve a fait accompli against Taiwan if the United States has allocated significant ISR resources to other theaters, thereby reducing the ability of U.S. forces to generate indications and warning in the Indo-Pacific. Beijing might therefore try to compel the United States to shift ISR resources away from the Indo-Pacific by encouraging Russia or Iran to escalate in their respective regions. Russia and Iran, in turn, might be inclined to do so not just because they receive some immediate benefit from China—for instance, supplies for Russia’s defense industry or the purchase of large quantities of Iranian oil—but because if they believe China will initiate hostilities shortly afterward, they may also believe that the United States is likely to shift forces from their respective regions in turn, at which point they will be in a much stronger position to pursue their own ambitions.

Crucially, the best way to deal with this risk is not by playing along with China’s or other adversaries’ attempts to spread U.S. forces thin. Rather, as argued in this paper, it is to concentrate U.S. forces where they are needed most—to defend the U.S. homeland and deny China’s imperial ambitions—while empowering allies and partners to lead in other theaters. In this way, Washington and its allies can reduce incentives for adversary coordination because, with U.S. and allied forces postured accordingly, even if they do coordinate, it will not meaningfully improve any of their respective likelihoods of success.

Bluffing. Alternatively, U.S. policymakers might try to bluff their way out of the simultaneity problem. This, too, seems to be part of the Biden Administration’s approach. In 2022, for instance, President Biden vowed to defend “every inch of NATO” after deploying tens of thousands of U.S. forces to Europe.REF In 2023, after Hamas’s attack on Israel, the Administration sent two carrier strike groups, a guided-missile submarine, air and missile defenses, and other units to the region to deter Iran and its proxies. The United States also cycles forces to the Indo-Pacific to reinforce deterrence in times of increased tension.REF

In effect, this strategy tries to convince every adversary around the world that the United States is ready and able to defeat it, and it succeeds as long as they are all convinced—but in reality, there is reason to doubt the credibility of such posturing. U.S. military limitations are increasingly apparent, especially since the war in Ukraine has highlighted shortfalls in U.S. munitions stockpiles.REF As a result, adversaries are increasingly likely to call America’s bluff. If they do, the United States may shift forces to the affected theater to try to restore deterrence. However, this will weaken deterrence in the theaters from which they are taken, incentivizing adversaries in those theaters to engage in opportunistic aggression, thereby generating risk of cascading escalation across theaters.

Risk of cascading escalation might be mitigated if allies and partners can fill in for departing U.S. forces. But bluffing tends to weaken burden-sharing by shifting U.S. forces across theaters in response to crises, thereby perpetuating allies’ and partners’ belief that America will be able to defend them in a time of war. As a result, a bluffing strategy not only entails a high risk of cascading escalation, but also can limit America’s ability to hedge against such a catastrophic outcome by strengthening burden-sharing.

Prioritization in Practice. A better approach is for the United States to prioritize.REF Under this strategy, the United States would focus forces first on defending the U.S. homeland and denying China’s imperial ambitions, most urgently by deterring China from invading Taiwan. The United States would assign forces that are not required for—and that do not need to be divested to free resources for—those top priorities to other missions such as defending Israel, NATO, or South Korea or conducting counterterrorism operations.

In an extreme scenario, Washington could still divert forces from defending the U.S. homeland or deterring China to defend Israel, NATO, or other allies, but this would come at the expense of America’s ability to accomplish those priority missions. Consequently, this option should be exercised only in the rarest of circumstances, and the United States should do everything possible to avoid having to exercise it in the first place.

Under the proposed defense strategy, the United States would therefore augment U.S. forces in every theater by strengthening burden-sharing. In Europe and the Middle East, the United States would seek to empower allies and partners to lead efforts to deter or defeat threats to our shared interests, including in the event of regional crises, with critical but more limited U.S. support. The United States would also prioritize burden-sharing in the Indo-Pacific—especially with Taiwan—which is vital to deter China.

The United States would do this not only by strengthening incentives for allies and partners to do more to defend themselves. It would also make it as easy as possible for them to do so, especially by reforming and expanding U.S. defense production;REF prioritizing exportability in defense acquisitions so that the United States can deliver key capabilities abroad more quickly and in larger numbers; overhauling U.S. arms transfer processes; and encouraging allies to increase their own defense production. Crucially, U.S. defense production would be aligned with U.S. priorities, focusing on U.S. forces, Taiwan, and Israel first, even as the United States sought to increase production so that trade-offs and delays were no longer as troubling. At the same time, by taking fuller advantage of allied defense production, the United States could reach production targets faster and create or strengthen economic incentives for allies to do more for their own defense.

But the United States can do only so much. Israel, Poland, India, South Korea, and certain other allies and partners regularly demonstrate a strong commitment to their own defense and are likely to keep doing so. Others do not—and still might not even if the United States worked deliberately to empower them to do so under the strategy proposed in this paper.

In some cases, America’s interests may be so great as to compel us to fight even if allies have not done all they can, assuming their negligence has not left the military situation unsalvageable. In others, even if the United States can still send some support, it will be unable to send all the forces required to defend free-riding allies without endangering its ability to secure higher priorities. Under these circumstances, Washington—as it has done in the past, especially during the Cold War—should be prepared to use every tool available, including coercive diplomacy, to persuade intransigent allies to do more.REF

What the United States Needs to Do

The following lines of effort will allow the United States to defend the U.S. homeland and deny China’s imperial ambitions while empowering allies and partners to lead efforts to defend against other threats. Taken together, they form the heart of the proposed defense strategy.

Homeland Defense. To strengthen homeland defenses:

• The United States should expand and diversify America’s nuclear deterrent by accelerating nuclear modernization, preparing options to upload additional warheads to existing intercontinental and submarine-launched ballistic missiles, and fielding a larger and more diverse array of theater nuclear options.
• Washington should deter adversaries from using WMD against the U.S. homeland by explicitly reserving the right to respond to such attacks with all available tools, including nuclear weapons.
• DOD should field a robust set of homeland missile defenses, optimized first to defeat limited missile salvos from a variety of actors, while pursuing options to defeat larger salvos on a cost-effective basis, including new technologies, greater reliance on space-based assets, greater emphasis on boost-phase defense and forward-deployed missile defenses, and (if feasible and necessary) preemption.
• DOD should support interagency efforts to defend against enemy cyberattacks, including by developing cyber and other offensive options to deter or defeat such attacks.
• The United States should be prepared to act and, if advisable, use force to prevent China or other adversaries from placing missiles or other forces in the Western Hemisphere where they can strike the U.S. homeland or disrupt U.S. power projection in the hemisphere and beyond.
• DOD should provide forces as part of a broader effort to secure America’s borders,REF including broad-area surveillance, maritime interdiction, military engineering, counternarcotics capacity-building and cooperation, intelligence collection, and options for direct action against high-value targets in the Americas.

Balancing Power in Key Regions. To strengthen deterrence against China:

• The Secretary of Defense should maintain a single-war force planning construct, with China as DOD’s pacing threat and a Taiwan contingency as its pacing scenario,REF to facilitate the concentration of DOD resources on ensuring America’s ability to deter or, if necessary, prevail in a war over Taiwan.
• DOD and other U.S. government agencies should intensify intelligence-gathering on Chinese forces so that the United States can engage high-value targets quickly in the event of a conflict. This may also help U.S. forces to make the best use of limited numbers of advanced munitions.
• The United States must surge production of weapons needed by U.S. forces to deter or defeat a Chinese invasion of Taiwan, including long-range anti-ship, land-attack, and air-to-air missiles, as well as air and missile defenses.
• The United States should expand AUKUS-style technology development and cooperation with other allies and close partners to complicate Chinese decision-making, with a particular focus on long-range precision fires, cheap disposable platforms, and missile defense information-sharing. An AUKUS “Pillar II”–style technology-sharing arrangement with Japan, Korea, and India would do much to leverage allies’ and partners’ expertise and industrial capacity.REF
• The United States must prioritize arming Taiwan with asymmetric defense capabilities, including by surging production and accelerating the delivery of anti-ship missiles, naval mines, mobile air and missile defenses, long-range precision fires, anti-armor weapons, UAVs, and associated training and other support, while ensuring that Taipei takes all necessary steps to strengthen Taiwan’s defenses as quickly as possible.REF This will include prioritizing Taiwan for security assistance using Presidential Drawdown Authority (PDA) and Foreign Military Financing (FMF) as well as War Reserve Stock authorities.
• DOD and other U.S. government agencies must accelerate the hardening and dispersal of U.S. operating locations in the Western Pacific, including Japan, the Philippines, Australia, and U.S. territories like Guam and the Northern Marianas, to complicate Chinese targeting and maximize the ability of U.S. forces to evade or withstand Chinese bombardment.
• DOD must take full advantage of dispersed basing by accelerating the development and implementation of concepts for distributed operations, including service-specific programs like the U.S. Marine Corps’ Expeditionary Advanced Base Operations and the U.S. Air Force’s Agile Combat Employment, along with enabling concepts, including for contested logistics.
• DOD must evaluate options to shift weapons from other regions to the Indo-Pacific with particular attention to submarines, air and missile defenses, and other assets that must be in position very early in a conflict to deny a Chinese fait accompli but will be difficult to swing quickly to the Indo-Pacific after an invasion begins or U.S. forces learn that an invasion is imminent.
• DOD must prioritize breaking through submarine and ship maintenance backlogs to ensure that these vessels are available for the current period of increased tensions while also accelerating production of key submarines, ships, and aircraft, including tankers and lift assets, to the extent possible given industrial constraints.
• DOD must evaluate options for keeping older platforms that are relevant to a Taiwan contingency at sea or in the air until DOD can field replacements at scale, such as selectively recapitalizing older guided-missile cruisers to augment Guam missile defenses even if they cannot fight forward in the Western Pacific or extending the service lives of older but still capable assets like Los Angeles–class attack submarines.
• DOD must accelerate the adoption and development of new capabilities that could make a difference in this decade, such as ground-based long-range precision fires to be fielded at scale by the Army and Marine Corps in the Western Pacific, along with their enablers; unmanned air, surface, and undersea systems, which could be used for a combination of sensing, targeting, and strike functions; and resilient military or dual-use satellite constellations.REF
• DOD must update U.S. nuclear doctrine, force structure, force posture, and plans, as part of broader efforts to expand and diversify U.S. nuclear forces, to provide the President with limited nuclear options he can use to deter or manage escalation following Chinese theater nuclear use.REF

To strengthen NATO and deter Russia:

• The United States should prepare a road map for NATO allies to take primary responsibility for Europe’s conventional defense by identifying U.S. forces assigned to NATO regional defense plans—particularly the defense of the Baltics, Poland, or Finland—that are also required to defend the U.S. homeland or deter China; identifying steps that Washington will take to support allied efforts to field replacements for U.S. forces identified in the road map as quickly as possible; and setting clear timelines for reposturing U.S. forces identified in the road map.
• The United States should strictly condition any further U.S. military aid to Ukraine to avoid trade-offs with Taiwan or Israel and maximize incentives for NATO allies to take the lead in supporting Ukraine’s defense, especially by increasing their own defense spending and production of relevant weapons.REF
• The United States should modernize America’s nuclear deterrent in Europe by fielding a larger and more diverse set of limited nuclear options and strengthening NATO nuclear burden-sharing on a cost-effective basis, potentially by forward-stationing U.S. nuclear weapons in Poland, Finland, and Romania, with offsetting financial contributions from allies.REF
• DOD should reinstitute the annual report on allied defense contributions, including details on NATO allies’ defense spending and industries, to increase transparency, discourage free-riding, and enable U.S. policymakers to make informed decisions to strengthen NATO burden-sharing.

To support Israel’s defense and deter Iran:

• DOD must maintain—or, as needed, develop—capabilities required to destroy Iran’s nuclear facilities, especially options for destroying HDBTs.REF
• The United States must increase defense production to meet Israel’s requirements for air and missile defenses, air-to-ground weapons, and other capabilities, such as tanker aircraft, while also providing Israel with targeting and other military support.
• The United States should expedite arms sales and delivery to Saudi Arabia, the United Arab Emirates, Bahrain, and other Gulf partners, along with associated training and other support, with the goal of strengthening the ability of these countries to deter or defend against Iranian air, maritime, and other threats with more limited U.S. support.
• The United States—and DOD in particular—should facilitate increased defense cooperation between Israel and Gulf partners, including consultations, coordination, and the sharing of information and technology, with a particular focus on countering Iranian air, missile, and maritime threats as well as Iran-sponsored terrorism.
• DOD must ensure that operational plans related to Israel’s defense rely as much as possible on fourth-generation aircraft, short-range air-to-ground munitions, and other capabilities not required for a Taiwan contingency so that the President has the option to send U.S. forces to defend Israel while still deterring China in the Indo-Pacific. Similar changes should be made in operational plans related to other Middle East contingencies.
• The United States should remove U.S. forces from vulnerable locations in Iraq and Syria, not only to save American lives, but also to prevent Iran from using those forces as leverage during crises and to free air and missile defenses for the U.S. homeland and Indo-Pacific.

To deter North Korea:

• The United States must help South Korea to field forces as quickly as possible to defeat a North Korean ground offensive, including by updating relevant operational plans and force requirements; urging Seoul to prioritize forces required for defeating a North Korean ground offensive—from ground and air forces to command and control, ISR, and other enablers—over other defense acquisition programs; and providing training and other support.
• Washington should transfer wartime OPCON of South Korean forces to Seoul as soon as South Korean forces can defeat a North Korean ground offensive or sooner, given limitations on America’s ability to supply conventional forces for a Korea contingency and the pressing need for South Korea to assume primary responsibility for countering a North Korean invasion.
• DOD must deter North Korea from using nuclear weapons or other WMD against South Korea or Japan by fielding a larger and more diverse set of U.S. limited nuclear options, enhancing nuclear coordination with South Korea, bolstering U.S. homeland missile defenses, fielding more robust and cost-effective theater missile defenses, and evaluating other options to ensure a credible defense of both allies, especially if it becomes clear that North Korea will be able to outpace and overwhelm U.S. homeland missile defenses.

To counter terrorism on a resource-sustainable basis:

• DOD should focus U.S. forces on terrorists that are capable of striking the U.S. homeland while supporting efforts led by allies and partners to engage other terrorist organizations.
• The United States should rely primarily on U.S. standoff capabilities and local partners, trained and equipped by U.S. forces as appropriate, to prevent relevant targets from using sanctuaries in the Middle East or other regions to execute attacks on the U.S. homeland.
• DOD should support efforts by other U.S. government agencies, allies, and partners to share intelligence, bolster homeland security, and take other steps to prevent terrorists from launching attacks on the U.S. homeland.

Conclusion

The unipolar momentREF is over, and the United States has a chance now to define what comes next. We can adhere to failed policies of the past, inviting only further crises, chaos, and destruction—perhaps even a third world war—as we are beginning to see. Or we can refocus America’s resources on the things that matter most for our citizens’ security, prosperity, and freedom.

By doing so, we can ensure that all Americans are able to live safely and with dignity. We can set conditions for the renewal of America’s alliances and partnerships around the world so that our friends, too, can live free from fear. We can force our rivals to come to terms with the futility of their imperial dreams. And we can do it all while husbanding our nation’s blood and treasure, which U.S. leaders have spent far too freely in the post–Cold War era.

There is a great opportunity before us—but that does not make prioritization any easier. Nor does it eliminate risks associated with this approach even if those risks are more tolerable than the risks associated with other strategies. U.S. policymakers should therefore keep looking for ways to solve the simultaneity problem and ease—if not eliminate—the prioritization imperative.

To that end, policymakers can and should look for ways to do more with the resources available to DOD, including by taking advantage of savings initiatives and technological offsets. They should also continue to advocate for higher defense spending as they see fit. As they do, however, they should be clear-eyed about the limits of these approaches: Even if they bear fruit, they are unlikely to do so soon. Washington might respond by trying to sequence between theaters or bluff its way out of the simultaneity problem, but the former is unworkable, and the latter is structurally disposed to catastrophic failure.

As a result, as long as scarcity persists, prioritization is and will remain the best way to defend America’s most vital interests in a more dangerous world.

Alexander Velez-Green is Senior Policy Advisor in the Douglas and Sarah Allison Center for National Security at The Heritage Foundation. Robert Peters is Research Fellow for Nuclear Deterrence and Missile Defense in the Allison Center.