This article was originally published in a 1998 issue of the Harvard International Review.

For the United States and its military, the last decade of the 20th century has been a transformative experience. No longer bound by the rigid bipolarity of the Cold War era, US foreign policy must now advance US interests in a much more fragmented, multipolar international system. Many of the old rules have changed, and how the United States uses its military to support its foreign policy has changed accordingly. Two trends have shaped the US military since the fall of the Berlin Wall: the dramatic downsizing of the armed forces and their increasing use in “non-traditional” missions. 

The US armed forces are now 40 percent smaller than during the Cold War, and US defense spending as a percentage of GDP is lower than at any time since World War II. Although much smaller, the military is now deployed more frequently than ever before in support of a national strategy of engagement—a strategy that rightly seeks to showcase US leadership of the democratic world. 

Without question, the instability which followed the collapse of the Soviet Union has placed a premium on US leadership. As the only remaining global power and as a coalition leader in international organizations such as NATO, the United States is uniquely positioned to influence world affairs in ways that benefit both the United States and the international community as a whole. The prudent use of military force, in concert with the economic, political, and diplomatic instruments of national power, is a central aspect of US efforts to shape the international environment and to encourage stability wherever vital interests are at stake. By remaining engaged, the United States is able to exert its influence to prevent crises from escalating, deter major wars, and help avoid the tragedies and conflicts that marred the 20th century. 

On any given day, the US military engages in missions ranging from maintaining a forward presence, to humanitarian assistance, to peacekeeping, to evacuation of US nationals from threatened areas. Experience in dozens of such operations has taught the US military several important lessons about how the armed forces can best support US interests and policies. 

One lesson is that while US forces have performed extraordinarily well in executing military tasks, such as separating combatants or safeguarding relief supplies, they are less effective in solving non-military problems rooted in religious, cultural, or ethnic enmities. In such cases, military force can help create a secure environment in which to pursue more lasting political and economic solutions. We should not, however, mistake this condition for a conclusive solution. Contemporary history teaches that the principal burden of peacemaking still remains on statesmen. For peacemaking to be successful in the long term, it must rely on an integrated approach that employs a range of policy tools and processes and that involves international and non-governmental organizations. 

A second lesson follows from the first. Never before has the need for closer collaboration between military leaders and the diplomatic community been more crucial. In almost every instance where US forces were deployed for humanitarian reasons, close cooperation with foreign militaries, governmental agencies, and non-governmental organizations from many different nations was required. The US military’s partnership with the US State Department, its close relations to the armed forces of countries around the world, and a growing familiarity with the international relief community have helped the United States conduct its foreign policy efficiently and have contributed to the success of the military’s operations. The capacity to function successfully as a team in complex, multicultural settings is an important development in the military’s ability to support US foreign policy objectives. 

The 21st century will undoubtedly be witness to more operations where US military forces will be called on to use their unique capabilities to provide humanitarian assistance or protect a fragile peace. But while US forces have shown themselves to be extremely flexible and adaptable in these situations, the United States must avoid the temptation of patterning its forces for the challenge of non-traditional missions while ignoring their central purpose: fighting and winning the major conflicts which pose the most serious threats to the United States and its national interest. 

Striking the right balance between traditional and non-traditional missions will be the key to the US military’s success in supporting US foreign policy as it meets the challenges of the next century.