The security alliance between the United States and the Republic of Korea (ROK) is the foundation for the architecture of strategic stability in Northeast Asia that has endured for more than a half century. Along with the U.S. alliance with Japan, this security architecture has maintained the balance of power despite vast geopolitical changes, not least the end of the global Cold War. It provided an environment that fostered spectacular economic growth and the institutionalization of democratic governance.

The stability created under this strategic architecture is now challenged by a unique combination of three developments—the rise of China, North Korea’s bid to become a nuclear power, and the weakening of the United States in the wake of the Iraq War.

These events disturb the carefully crafted balance of power that was created during the Cold War era. China’s growth as an economic and military power, combined with its aspirations for regional leadership, creates an alternative pole of power to the United States. The defiant decision of the Democratic People’s Republic of Korea (DPRK) to test a nuclear device threatens the security of Korea and Japan and opens the door to further proliferation in the region.

These two developments have been widely discussed among policymakers and experts in the region and in the United States. But there has been little examination of the dangerous dynamic between these events and the Iraq War. The deteriorating military and political situation in Iraq and in the Middle East more broadly has significantly weakened the United States in East Asia. It has swung public opinion against the United States and, as collateral damage, undermined support for the alliances. The focus of U.S. attention and resources on the Middle East feeds a perception that U.S. interest in East Asia is declining. More profoundly, it encourages powers such as China and Russia to assert more frequently and more boldly their desire for a more multipolar power structure.

The war has also depleted the U.S. force structure in the Pacific, drawing all the U.S. Army and Marine Corps ground forces committed to the Pacific theater into active deployment in Iraq. The global redeployment of U.S. forces has already produced a significant drop in force levels in Korea and plans are to move forces currently based in Japan to bases in Guam and elsewhere. Although U.S. naval and air forces in the Pacific remain at significant levels, it is not credible that the United States could commit large numbers to the defense of Korea in the event of a major conflict.