In spring 1941, months before the bombing of Pearl Harbor, a team led by U.S. Naval Intelligence officer Kenneth Ringle broke into the Japanese consulate in Los Angeles.

One man stayed downstairs to guard the elevator while the rest snuck upstairs using skeleton keys to make their way to the back rooms. They brought along a safecracker—a convicted felon sprung for one night to help them—as well as local policemen and FBI agents, who set up patrols outside during the …