In late May, a shipment of F-35 stealth fighter jet parts heading for the United States from Australia was misrouted to Hong Kong and into Chinese hands. Since 2007, Chinese intelligence operatives and their proxies had been stealing data to do with the F-35. Now, some of the jet’s closely guarded components, including a cockpit canopy and weapons-bay door, had landed on Chinese soil—handing Beijing stealth technology that only the United States and its allies have access to. China will surely attempt to reverse-engineer the technologies it was lucky to acquire. U.S. officials do not believe there was foul play here and they think the delivery was likely an accident: the result of a shipping delay and a missed email. But even without active foreign interference, the mere logistics of coordinating F-35 production and delivery among Washington, Canberra, Lockheed Martin, and a third-party shipping company exposed defense secrets to the greatest U.S. rival.

The U.S.…