The bluff that worked and backfired

The incident was a deliberate British bluff that demonstrated what Royal Navy cruisers could do near Japan. It succeeded as a display of reach and professional boarding skill, while deepening Japanese resentment and exposing the hazards of uncertain international law. Britain eventually returned nine of the twenty-one Germans in exchange for Japan agreeing not to transport German merchant sailors again. Those nine had initially appeared potentially useful to the German war effort, but later examination reduced their assessed military value; the remaining twelve stayed prisoners for the rest of the war. The operation shut down a manpower route but carried the serious risk that an encounter with a Japanese cruiser could escalate the crisis.