Q: What does the idiom just a hair off mean?

A: Usually, it means "Very close" as in, "a hair's width," as in, "you missed your target ever so sightly, but you shouldn't beat yourself up; in fact, you should feel proud for even trying."

But I meant it differently.

When you asked if you had successfully hit the target and I shook my head and raised my hand in front of face, holding my index and middle fingers an inch apart, and I looked at you through the space between my fingers and I said, "You were just a hair off," I was being sarcastic. That's why General McCloskey laughed, and why General Bailey laughed, and why President Percival laughed and then began to cry. Because I was being sarcastic. Because I meant the exact opposite.

Your mission was to bomb Damascus, in Syria. You bombed Cincinnati, in Ohio.

Soldier, you cost us a swing state.