Beijing also claims the 1.4 million square-mile South China Sea – rich in fisheries as well as undersea oil and gas. In April it entered a tense standoff with the Philippines over rights to part of the ocean. Malaysia, Taiwan, and Vietnam claim all or part of the South China Sea as well.
Then there is the matter of the US being obligated by security pacts or acts of Congress to help defend Japan, Taiwan, and the Philippines – all located off the east coast of rising military power and US cold-war rival China. But today the US also needs China, a low-cost manufacturing base and major market for US exports. An open conflict among disputants could throw US trade, shipping, and naval exercises out of whack.