On Sunday near Okinawa, the Japanese navy spotted two Chinese warships sailing south into the Pacific. The Chinese vessels were in international waters, but their proximity to Okinawa, which hosts a preponderance of U.S. and Japanese military forces, alarmed Tokyo. As a courtesy, navies traditionally announce their routine cruises in advance, particularly when one nation's ships might pass close to another's territory.
Sunday's infraction of that protocol was not the first for China. Just three months prior, two Japanese warships patrolling around Okinawa had discovered an unannounced flotilla of at least 10 Chinese vessels, including two submarines. During the encounter, a Chinese helicopter buzzed one of the Japanese ships, eliciting a formal protest from Tokyo. ...