近年來美國經濟力量的下滑，與中國大陸的經濟和軍事力出現明顯對比。在此背景下，美國的「再平衡」戰略應運而生。美國及東亞盟國安全威脅主要來自北京和北韓，因此他們同屬「再平衡」戰略的對象。美國推動「再平衡」戰略，必然通過多重形式，包括增強與亞太國家軍事合作。經濟方面，美國推動《跨太平洋戰略經濟夥伴協定》，以增強和東亞國家的經貿合作。在美國「重返亞洲」的框架中，朝鮮半島和平穩定成為焦點，惟南北韓關係迄未好轉。另北京對兩韓的影響也在增強，美國推行「再平衡」戰略時，同樣將承受來自北京的制約。

Given the decline of the American economy, along with the rise of Chinese economic and military capability, the United States and its Asian allies feel uneasy and yet are eager to cope with this adverse situation. To operate a ”Rebalancing” strategy, the United States has to adopt multiple measures, including strengthening the economic and defensive capability of American allies and keeping firm commitments to its allies. China and North Korea are, in fact, the primary target of this American strategy. In addition to its strategic buildup, the United States also wields the TPP as an economic instrument. Washington has strengthened its ties with Japan and South Korea under the framework set up by Obama, but unfortunately North-South Korean relations are still in a state of hostile stalemate. Since China has been a powerful actor in Korean affairs, Obama's ”Rebalancing” strategy is inevitably constrained by Chinese policies.