Since the U.S. presedient Obama took over his postition in 2009, the U.S. Department of Defense published the Quadrennial Defense Review (QDR) to reexamine the U.S. military planning and national strategy by law. This QDR mentions the rebalancing and shaping of the military force, building the security capacity of partner states, and it also puts emphasis on returning to Asia, expanding future long-range strike capabilities and enhancing the presence and responsiveness of forces abroad. The purpose is to focus on the nations which influence American benefit, and to deter and defeat aggression in anti-access environments. To face the condition of financial austerity in recent years, the U.S. will turn toward regional balance in the Pacific area as a strategic goal under the challenge of future security environment, share the cost by looking for new partner states, reach the safety goal through innovation, low cost and less request for logistics, strengthen the standard of international behavior with partnerstates, andmaintain the military ability of interoperation.
This study is to dicuss the role and function of US-Japan alliance in Joint Operation Access Concept (JOAC). Since the U.S. signed the “Treaty of Security and Safeguard between Japan and the United States” with Japan and deployed the U.S. military in Japan by the strategy of Asia-Pacific rebalance and JOAC to defeat the anti-access / area-deny operation. Through the change of the key element of the military deployment in Japan military base and joint military exercise, this study demonstrates the change of the strategic focus of the U.S. and Japan, and forcasts the future development trend by comparing and contrasting the theories and practices, analyzes how the US-Japan alliance defeats the anti-access / area-deny operation by JOAC. Based on this situation, this study is the research on the collaborative project of the US-Japan alliance, and the assessment of the influence on the security of Asis-Pacific area in order to find the role and position of ROC in JOAC.