Charles Krauthammer thinks Barack Obama is going to win the election. More interestingly, he uses a revealing metaphor: “Krauthammer’s Hail Mary Rule: You get only two per game. John McCain, unfortunately, has already thrown three. The first was his bet on the surge, a deep pass to David Petraeus who miraculously ran it all the way into the end zone.”

In case you’re not a football fan, the essential characteristic of a “hail Mary” pass (just hurling the ball downfield in the direction of the end zone) is that it’s a bad play. Which is to say that the expected value of such a pass is extremely low. But sometimes you throw one at the end of a game if you’re in a situation where any play other than a successful “hail Mary” will result in your team losing the game. Under those circumstances, the fact that the play has only a low chance of succeeding isn’t relevant. It’s important to note, however, that the logic behind the play depends crucially on the fact that a football game is a zero-sum enterprise with bivalent outcomes. You either win or lose, there’s no middle ground. And if the other guys win, you lose.

Some things in life are like that. Notably, many games. But also US Presidential elections. Significantly, though, prolonged wars of choice aren’t like that at all. Iraq is the kind of situation where a whole range of possible outcomes is possible, it involves more than two players, and the interactions between the players aren’t zero sum. It’s not, in other words, at all the kind of situation in which it’s appropriate to throw a metaphorical hail Mary. Unless, that is, you’re thinking of Iraq policy primarily as an electioneering gambit.

But now Richard Oppel reports for The New York Times that things are changing and the Iraqi government, feeling newly confident, is in the midst of a crackdown with senior leaders of the awakening movement getting arrested.