Providing for the common defense is one of the paramount responsibilities of the United States government. To do so most effectively and cost-efficiently, the U.S. military’s missions should be driven by America’s national security strategy and enduring vital interests.

Drawing from authoritative and open-source documents such as the Defense Department’s 2010 Quadrennial Defense Review[1] (QDR) and the 2010 congressionally chartered QDR Independent Panel report,[2] The Heritage Foundation, in a forthcoming report, has mapped key commitments to the elements of U.S. force structure that are required to secure U.S. vital interests and has outlined the cost implications and affordability of sustaining robust armed forces. A summary of the findings of this study follows.

Broad Considerations

Other elements of national power such as diplomacy—assuming that they are in place—are often most effective when supported by credible military force. Ultimately, beyond the missions necessary to protect America directly, U.S. contributions to collective security should be determined by what best serves the nation’s vital interests. Such determinations should, however, be made in light of the understanding that the U.S. and its allies retain mutually beneficial contributions, with allies providing resource and access opportunities to balance advanced American capabilities.

Policymakers should prepare for unexpected threats while balancing this need against what the nation can afford. Without such preparations, though, short-term savings will be completely undermined by long-term expenditures to either recover or adapt to changing security situations and catastrophes.

Regional Threats

America’s external threats are complex and far-ranging. Within Asia, China’s military buildup and advanced technological developments threaten America’s ability to project power in the western Pacific. Operations with Pakistan and in Afghanistan continue to consume military resources with extensive operations to counter the Taliban and al-Qaeda threats. While the U.S. should not summarily support a drawdown in 2014 without regard to conditions, al-Qaeda is attempting to move some of its operations to Yemen and elsewhere.

North Korea and Iran also continue to pose significant risks, with both countries proceeding with their ballistic missile and nuclear programs despite international sanctions. Both also represent an elevated risk of technological proliferation to non-state entities and proxies such as Hezbollah.

Europe faces a number of risks on its eastern borders, with Russia continuing to influence former Soviet bloc states and Turkey drifting toward a more Islamic foreign policy.

Securing the Homeland

As highlighted by the recent earthquake in Japan, all nations must be well prepared to respond in the event of a major disaster—whether natural or man-made—and recovery from its effects. Given current force deployments and the high tempo of operations, it is questionable whether there are sufficient military resources available to deal with a similar catastrophe in America today.

The American homeland is faced with a range of additional threats, including terrorist attacks, cybersecurity, border protection, and transnational criminal cartels. The military can play a key role in defending against all of these, not by serving as first responders but by assisting during major disaster relief operations and helping with prevention. The loss of access to space would also create a tremendously devastating impact on the country, denying use of essential components of both military capabilities and America’s economic prosperity.

Force Structure

The basic force summary roll-up provided in this analysis aligns generally with the Pentagon’s force structure as determined in the QDR as the minimum required to meet security requirements. It also contains additional investment in modernization of the force and acquiring select additional capabilities as outlined in the QDR Independent Panel’s report. Specifically, the panel notes that the Department of Defense’s force structure as laid out in the QDR may not allow the U.S. military to fully meet the nation’s commitments in Asia due to increased Chinese military capabilities.

The panel proposes an alternative force structure that is fully modernized. This alternative is appropriate to match the security threats facing the U.S. and includes

modernization in areas where modernization is needed but not currently planned for the short term—submarines, a next generation cruiser, a tanker and lift capability, and new ground combat vehicles. Second, the recommended force emphasizes long-range platforms to a greater extent than the current force. We believe this will allow the United States to protect its vital interests at low to moderate risk over the coming two decades. … Force structure must be strengthened in a number of areas to address the need to counter anti-access challenges, strengthen homeland defense (including defense against cyber threats), and conduct post-conflict stabilization missions.[3]

To address concerns about military power in Asia, the panel recommends that U.S. presence in the region should continue, since it is responsible for the stability that allowed the economic emergence of India and China.

The panel also recommends increased investments in other areas:

We recommend an increased priority on defeating anti-access and area-denial threats. This will involve acquiring new capabilities, and … developing innovative concepts for their use. Specifically, we believe the United States must fully fund the modernization of its surface fleet. We also believe the United States must be able to deny an adversary sanctuary by providing persistent surveillance, tracking, and rapid engagement with high-volume precision strike. That is why the Panel supports an increase in investment in long-range strike systems and their associated sensors. In addition, U.S. forces must develop and demonstrate the ability to operate in an information-denied environment.[4]

Budget Requirements

To provide for the requirements of a fully funded force structure grounded in strategic requirements, the core defense budget would need to average about $720 billion from fiscal years (FY) 2012 through 2016. Compared to the President’s proposed defense budget—excluding war spending—in FY 2012, Congress would need to add slightly more than $27 billion in budget authority to initiate the recovery process.

Maintaining stable, robust defense spending levels that allow for real growth would enable the U.S. to maintain stable troop levels while retaining the all-volunteer force training and experience. It would allow the U.S. to maintain stable readiness funds, adequate investment in research and development, and a procurement spending level of 1.5 times the research and development budget both to modernize the nation’s conventional and strategic forces and finally to recover from the post–Cold War “procurement holiday.” Ultimately, this would allow the military to maintain existing security commitments, including the capacity to secure the global commons, prevent the rise of hostile powers in key regions abroad, and respond flexibly to unanticipated dangers.

Long-Term Ramifications

Adequate defense funding is affordable. To sustain this force over time, however, requires addressing (1) mandatory federal government outlays that, if unchecked, will consume the entire federal budget; (2) defense manpower costs that will need to be controlled without cutting overall manning levels; and (3) wasteful, unnecessary, and inefficient defense expenditures.

Reducing U.S. forces below strategic requirements also presents grave risks to U.S. prosperity and economic growth. The military’s reliability has reassured allies and deterred potential adversaries from aggression. If the U.S. lacks the capacity to protect its vital interests, both the security and economy of the nation will suffer in the long term.

James Jay Carafano, Ph.D. , is Deputy Director of the Kathryn and Shelby Cullom Davis Institute for International Studies and Director of the Douglas and Sarah Allison Center for Foreign Policy Studies, a division of the Davis Institute, Mackenzie Eaglen is Research Fellow for National Security in the Allison Center, and Baker Spring is F. M. Kirby Research Fellow in National Security Policy in the Allison Center at The Heritage Foundation.