Contrary to what many politicians and talking heads tell Americans, a false choice exists between what are often referred to as hard and soft power. A country's military resources (its hard power) and the diplomatic tools it uses to persuade others without resorting to coercion (its soft power) operate most efficiently in tandem.

As Teddy Roosevelt famously observed, a nation must "speak softly" with diplomacy while also wielding a "big stick." Just as no country can be expected to provide security and pursue its interests solely through the use of military power, no country can expect to be taken seriously during high-stakes negotiations without the potential threat of military force to back up its word. The two approaches are not separate tools but mutually reinforcing mechanisms.

The Limits of Soft Power

To witness the consequences when policymakers and politicians believe that hard and soft power are disconnected, one need look no further than Europe. The Europeans--many of whom believe that the peace that has broken out on their continent is the model for a post-sovereign world order--have become convinced that the anarchic order of the Westphalian system of nation-states can be breached through the exercise of soft power alone. In their view, bridging the often hardened differences between states and shaping their decisions requires only negotiation and common understanding.

Many liberals are now pressing the U.S. government to adopt this vision, but the futility of this approach can be seen everywhere, from the failure of negotiations to deter both Iran and North Korea from their nuclear programs over the past five years--a period in which their efforts have only matured--to the lackluster response to Russia's invasion of Georgian territory.

Whether it is states like Iran and North Korea that believe a nuclear weapons program is central to regime survival, or human-rights abusers like Sudan, Burma, and Zimbabwe, or rising powers like China, which continues to use its military to emphasize its sovereignty in the South China Sea, diplomacy alone has not been enough to bring about change in a direction that is favorable to America's interests.

At times, America and its leaders have also been guilty of this type of strategic myopia. After applying pressure on North Korea so diligently in 2006, the Bush Administration relaxed its posture in early 2007, and North Korea concluded that it was again free to backslide on its commitments. Two years later, this weak diplomatic approach, which the Obama Administration continued even after North Korea's April 5 missile test, has only brought North Korea to believe that it can get away with more missile tests and nuclear weapons detonations. And so far, it has.

Backing Carrots with Sticks Works

In the past, when America chose to flex its diplomatic muscle with the backing of its military might, the results were clear.

During the Cold War, the foundational document for U.S. strategy toward the Soviet Union, NSC-68, concluded that military power is "one of the most important ingredients" of America's national power. This power gave the U.S. the ability not just to contain and, if necessary, wage war against the Soviet Union and its proxies, but also, during tense diplomatic stand-offs like the Cuban Missile Crisis, to reinforce its political objectives with robust strength.

This same equation of military-diplomatic power proved effective in easing tensions during the Taiwan Strait crisis in 1995-1996, when President Bill Clinton sent two aircraft carriers to demonstrate America's firm commitment to the Taiwanese democracy. Similarly, the display of America's military strength against a defiant Saddam Hussein in 2003 convinced Libyan President Moammar Qadhafi to abandon his weapons of mass destruction program.

Obama's Risky "Rebalancing" Act

Before he became President , Barack Obama raised the important connection between our hard and soft power, arguing that America must "combine military power with strengthened diplomacy" while also building and forging "stronger alliances around the world so that we're not carrying the burdens and these challenges by ourselves."[1] While his statements are correct, his actions as President have done little to demonstrate actual commitment to forging a policy that combines America's military power with its diplomatic authority.

For America to be an effective leader and arbiter of the international order, it must be willing to invest in a world-class military by spending no less than 4 percent of the nation's gross domestic product on defense.[2] Unfortunately, President Obama's FY 2010 proposed defense budget and Secretary Robert Gates's vision for "rebalancing" the military are drastically disconnected from the broad range of strategic priorities that a superpower like the United States must influence and achieve.

Instead of seeking a military force with core capabilities for the conventional sphere to the unconventional--including a comprehensive global missile defense system[3]--in order to deter, hedge against, and if necessary defeat any threat, Secretary Gates argues that "we have to be prepared for the wars we are most likely to fight."[4] He is echoing the view of President Obama, who has argued that we must "reform" the defense budget "so that we're not paying for Cold War-era weapons systems we don't use."[5]

But the conventional Cold War capabilities that this Administration believes we are unlikely to use are the same platforms that provide America with both the air dominance and the blue-water access that is necessary to project power globally and maintain extended deterrence, not to mention free trade.

The Importance of Sustaining Military Power

The consequences of hard-power atrophy will be a direct deterioration of America's diplomatic clout. This is already on display in the western Pacific Ocean, where America's ability to hedge against the growing ambitions of a rising China is being called into question by some of our key Asian allies. Recently, Australia released a defense White Paper that is concerned primarily with the potential decline of U.S. military primacy and the implications that this decline would have for Australian security and stability in the Asia-Pacific. These developments are anything but reassuring.

The ability of the United States to reassure friends, deter competitors, coerce belligerent states, and defeat enemies does not rest on the strength of our political leaders' commitment to diplomacy; it rests on the foundation of a powerful military. Only by retaining a "big stick" can the United States succeed in advancing its diplomatic priorities. Only by building a full-spectrum military force can America reassure its many friends and allies and count on their future support.

Kim R. Holmes, Ph.D., is Vice President for Foreign and Defense Policy Studies and Director of the Kathryn and Shelby Cullom Davis Institute for International Studies at The Heritage Foundation and author of Liberty's Best Hope: American Leadership for the 21st Century (2008).