I talk to many old warriors, from different branches of service and different wars. But after the many conversations I’ve had, I’m still in awe of selfless American bravery. One example of this is Maj. William Keller, with whom I recently chatted.

Keller graduated high school in 1968. “Back then,” he told me, “if you had two legs and you could stand, you were going in the Army.” Keller was the sole surviving son of a widow. He qualified for full deferment. “That didn’t feel right,” he said. At dinner every night, his family watched Walter Cronkite give the latest body counts. “It was pretty intense to watch.”