U.S. prominence in Asia since World War II has rested on a widespread belief among friends, foes and nonaligned nations alike that Washington would use its economic and military power to prevent what it saw as dangerous challenges to the region's peace, stability and growth.
This conviction was eroded in recent years as various U.S. administrations pursued different, and often confusing, approaches to Asia. While America bounced back from defeat in the Vietnam War, its current performance in Iraq and Afghanistan shows a lack of staying power.
The relative economic decline of the United States and its key Asian ally, Japan, have reinforced regional perceptions that America and the U.S.-led alliance system are no longer as dependable as before. The rapid, seemingly unstoppable, rise of China has strengthened its claim to be an alternative pole.