I met Gen. Vo Nguyen Giap—who died on Friday—twice. The first time was in the Vietnamese military hospital where I was taken shortly after my capture in 1967. My father commanded all U.S. forces in the Pacific, which made me an object of curiosity in some quarters of the North Vietnamese government.

I remember several high-ranking visitors in addition to the guards and interrogators I saw daily. Giap, North Vietnam's minister of defense, was the only one I recognized. He stayed only a few moments, staring at me, then left...