As state-sponsored hackers working on behalf of Russia, Iran, and North Korea have for years wreaked havoc with disruptive cyberattacks across the globe, China’s military and intelligence hackers have largely maintained a reputation for constraining their intrusions to espionage. But when those cyberspies breach critical infrastructure in the United States—and specifically a US territory on China’s doorstep—spying, conflict contingency planning, and cyberwar escalation all start to look dangerously similar.