In The Future of War — Dick Cheney, Mr. Cheney brings up the new demographics of our professional armed forces:
It’s also true that a large part of our force is married. They have families. I keep running into what people call the birthday problem. The first time somebody said that to me, I said, “What do you mean, the birthday problem?” He was an active duty officer. He said, “The third time you miss your kids’ birthdays in a year because you’re deployed, you begin to wonder about whether or not you ought to re-enlist.”