An unprecedented co,mplicating and sharpening situation has been developing in China s peripheral security since the end of the Cold War in 1991. First,the Pentagon is stepping up the U.S.military presence in the Asia-Pacific region for the second time in the post-Cold War period by setting up a naval marine base at Darwin port in Australia,re-stationing its troops in the Philippines,and planning to redeploy 60％ of its naval force in this area.Meanwhile,it has been beefing up its alliances by deploying littoral combat ships in Singapore;global hawk unmanned aerial vehicles (UAVs) or drones in Japan and South Korea;Osprey Transport Aircraft in Okinawa;the second set of intercepting missile radars in Japan,and urging Seoul to join its Asian missile defense system.Furthermore,it is boosting its defense cooperation with India,Indonesia and Vietnam in a bid to overpower and even isolate China in the vast region.