The United States of America is the world's only 'superpower'. Since the collapse of the Soviet Union and the end of the Cold War, only the US has maintained a balanced strategic nuclear capability, including modern versions of intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and long-range strategic bombers, as well as comprehensive and sophisticated global command, control, communications and intelligence (C3I) systems.
And only the US possesses the ability to engage in major conventional conflicts anywhere around the globe. Few other countries are able to deploy and sustain substantial military forces much beyond their own region, even in coalition operations. In fact, a fundamental basis of US defense planning since 1991 has been the requirement to fight and win two simultaneous major regional conflicts (MRCs), now called major theater wars (MTWs). It is generally assumed that one of these theaters is likely to be in Asia.
However, since the end of the Cold War, one of the principal Security concerns throughout much of the Asia-Pacific region, shared by policy-makers and independent analysts alike, has been about the integrity of the US presence in and commitment to the region. Some Asians believe that an American withdrawal is inevitable, or, at least, that the US will lose its ability to balance the growing capabilities of the major regional countries (i.e. Japan and China). The apprehensions about the future US commitment have contributed to the pervasive strategic uncertainty throughout the region, as well as to larger defense build-ups in some countries.
In fact, the US will remain deeply involved in the region. The financial and economic dimension of this has been expressed by the massive American aid and loans to the countries hardest hit