Chinese jets repeatedly buzzed a Canadian plane monitoring North Korea, sometimes coming so close that the pilots could see each other. Hundreds of miles to the south, a Chinese fighter plane sprayed metallic chaff in the path of an Australian surveillance craft, a maneuver that Australia called ¡°very dangerous.¡±

To Chinese officials, these were reasonable responses to foreign military patrols that threatened China¡¯s security. To the U.S. allies, the Chinese pilots¡¯ actions in recent weeks were worrying escalations, risking a midair collision or crash.

Such a mishap could trigger a broader conflict. ¡°There are split-second differences between this being a passing headline and this being a major incident with enduring international ramifications,¡± said John Blaxland, a professor of security and intelligence studies at the Australian National University in Canberra.