China has ended the post–Cold War peace in East Asia by claiming, contrary to international law, sovereignty over most of the western Pacific Ocean, by rapidly increasing its military capability, and by bullying its neighbors. China’s aggressive policies stem from the Chinese version of nationalism, which sees China as having the right to exercise dominance in the region. Chinese aggression stems also from Xi Jinping’s desire to maintain public support for, or at least tolerance of, the dictatorship of his Communist Party—which the slowing of economic growth threatens—by presenting himself as China’s champion against foreign enemies. China has also increased the threat to the region through its support for North Korea, with its nuclear weapon program.