Pyongyang had sent some special forces to spy on South Korea, but the mission went horribly wrong. Here’s What You Need to Remember: Since the end of World War II, the United States has routinely employed ships and aircraft on spying and observation missions of varying legality—and every now and again, something has gone wrong. A too-stealthy American submarine bumps into a Russian counterpart, a spy ship off Korea gets seized, a U-2 spy plane gets shot down, or a Navy P-3 collides with a Chinese fighter and is forced to land in Chinese territory. In the event the spies can’t return to home base, they’ve mostly surrendered to local troops and were eventually repatriated after interrogation and diplomatic wrangling.