Could Beijing and Moscow coordinate a pair of crises that would drive two separate U.S. military responses?
The United States faces more difficult problems in the Pacific. Japan or India might have an interest in the South China Sea, but this hardly guarantees their participation in a war (or even the degree of benevolence of their neutrality.) The alliance structure of any given conflict would depend on the particulars of that conflict; any of the Philippines, Vietnam, South Korea, Japan or Taiwan could become China’s primary target. The rest, U.S. pressure aside, might well prefer to sit on the sidelines. This would put extra pressure on the United States to establish dominance in the Western Pacific with its own assets.
The United States discarded its oft-misunderstood “two war” doctrine, intended as a template for providing the means to fight two regional wars simultaneously, late last decade. Designed to deter North Korea from launching a war while the United States was involved in fighting against Iran or Iraq (or vice versa,) the idea helped give form to the Department of Defense’s procurement, logistical and basing strategies in the post–Cold War, when the United States no longer needed to face down the Soviet threat. The United States backed away from the doctrine because of changes in the international system, including the rising power of China and the proliferation of highly effective terrorist networks.