I almost died in North Korea, once, and I don’t mean during my diplomatic trip in 2014 to free two Americans imprisoned there.

It was 1985, and I was the chief of intelligence for United States forces in South Korea. I was in a helicopter, on my way to check out what we suspected was a North Korean tunnel, when I heard a sound like popcorn popping and saw white puffs below us. This was followed by a loud alert in my earphones — “Red dog fox! — indicating someone had crossed the Demilitarized Zone. That someone was us.

After some evasive maneuvering, our pilot returned us to South Korean airspace and then home. A few days later a nervous South Korean commander showed up to apologize for an M-60 machine gun round that had struck our main rotor. The commander explained that South Korean troops assumed any aircraft flying north was defecting. We’d taken fire from both the North and South, and the South Koreans were better shots.

Most days were not that adventurous. I had been asked by the United States forces commander to provide him with 48 hours of “unambiguous warning” ahead of a North Korean invasion, so that he could evacuate all American dependents and prepare to defend the peninsula. It took me almost a year of study to decide that his demand was impossible to meet. I finally told him that the first unambiguous indication of an attack would be artillery shells falling on Seoul.