I've said before the lessons I think other generals will draw incorrectly from the fall of David Petraeus. His real mistake, I think, was going directly from four-star command to the directorship of the CIA. Rather, he should have taken some time out and reoriented himself. So the real lesson, I think, is that the time of retirement from high position is a vulnerable moment.

I didn't think much of Dick Cheney as a vice president, but I think he was a good defense secretary. I remember being told that when he left that job, he got in a car and drove across the country alone. Another thing to do might be to go camping or sailing for a few weeks. The point is to get out of the bubble, re-connect to the world, and most of all, catch your breath.