President Obama's hosting of the leaders of the 10 members of the Association of the Southeast Asian Nations (ASEAN) shows that Obama regards that region as the hinge of what has turned out to be a sluggish "pivot to Asia" in American strategy. This pivot from the U.S. emphasis on Europe and the Middle East during the Cold War and after is regarded as important because the nations of East Asia have had tremendous economic growth and are now experiencing security issues with the seeming juggernaut of a rising China. Obama's pivot to Asia has been distracted by continuing conflicts in the Middle East and Russia's annexation of Crimea and destabilization of eastern Ukraine. Meanwhile, China continues territorial disputes with Japan in the East China Sea and some of the ASEAN members in the South China Sea.
So far, the pivot has entailed allocating more U.S. military resources to East Asia -- for example, sending Marines to Australia and more naval assets to the U.S.-controlled island of Guam -- and beefing up formal and informal Cold War alliances in the region and improving relations with former enemy Vietnam, which has a historic rivalry with China. Also, the United States and China are competing for "economic power" in the region with the U.S. Trans-Pacific Partnership trade pact, which deliberately excludes China, and China's creation of a development bank for the region that rivals similar U.S.-dominated financial organizations. As for ASEAN -- the third largest economic entity in East Asia after China and Japan -- it has more trade with China than with the United States, but the United States has greater investment in the nations of the group than does China.
Despite their extensive economic ties with China, however, these nations of growing wealth want U.S. protection against a China that wants more influence the East Asian region. To provide this protection by containing China (the U.S. government refuses to call it that) the United States uses military forces already stationed or recently reinserted into countries of the "first island chain" that block China's access to the open Pacific Ocean - -Japan and the Philippines. The United States also has an informal alliance with Taiwan, which could act as an unsinkable aircraft carrier in any war with China by hosting U.S. aircraft flown in from other places. In addition, the United States stations forces in South Korea, Australia, and on the militarized island of Guam (in the second island chain impeding China's access to the Pacific) and regularly has its warships call in other Southeast Asian countries -- for example, Singapore and even Vietnam. However, this forward-based containment strategy, reminiscent of the Cold War, is out of date and unsustainable.
With China's rapid economic growth and concomitant improvement of its military, as well as the increased vulnerability of U.S. aircraft carriers and forward bases to Chinese weaponry, a time will come when the proximity of China to East Asia will allow it to have local ascendancy over a faraway American superpower saddled with almost $19 trillion in national debt. Vis-à-vis the United States, China has an asymmetric and defensive area denial/anti-access strategy to keep U.S. power projection forces -- read: U.S. aircraft carriers with accompanying surface warships -- out of waters near China. China has mines, diesel and nuclear-powered submarines, anti-satellite weapons, sophisticated land-based aircraft, and ballistic and cruise missiles that can put at risk vulnerable surface ships, especially large aircraft carriers. Furthermore, China's missiles can make large unhardened U.S. military bases in the region vulnerable to destruction.
Overall, China is by no means militarily superior to the United States and will not be for a long time. However, the United States has invested in vulnerable aircraft carrier battle groups for global power projection, which waste many naval resources defending themselves from possible attacks from the air, sea, and undersea at the expense of projecting offensive power. So it is increasingly possible that China, with continued economic growth and military enhancement, could make life very difficult for U.S. forces half a world away in East Asia.
For American hawks, this reality means that the United States should spend more on defense than the $600 billion a year currently being misallocated and which is already equivalent to the combined expenditure of the next seven highest nations in security spending. But even with such higher spending that the debt-ridden U.S. Empire cannot afford, China eventually could very well best the U.S. military locally in East Asia.
The realist foreign policy school talks as if conflicts between rising and status quo powers are inevitable, but in the 19th century, the British Empire, with a great ocean buffer to ensure its security, peacefully let the rival United States rise. With an even larger ocean providing the United States strategic depth from China and with nuclear weapons as the ultimate guarantor of U.S. security, the United States has the luxury of abrogating forward-based alliances that merely protect free-loading rich countries, withdrawing its military forces from East Asia to still forward installations in Guam and Hawaii, and peacefully letting China rise into a regional power in East Asia.