NEW DELHI – During his 13 years in power, Xi Jinping has steadily tightened his grip on all levers of authority in China – the Communist Party of China (CPC), the state apparatus, and the military – while expanding surveillance into virtually every aspect of society. Yet his recent purge of nine top-ranking generals, like those before it, shows that he still sees enemies everywhere. After taking power in 2012, Xi launched a crackdown on corruption within the CPC and the People’s Liberation Army (PLA). The campaign was initially popular, because China’s one-party system is rife with graft and abuse...