The current conventional wisdom is that Bush and McCain were right, and Obama wrong, about the Surge. That seems to me a half-truth.
Certainly it’s true that strong predictions that the Surge would fail have been disproven. At the time, Gen. Petraeus was quoted as saying that the surge had a 25% chance of working, which is slightly better odds than a one-card draw to a flush. Others thought that the odds were worse than that, more like filling an inside straight. Since we don’t get to re-run the experiment, there’s no way of telling what the correct prior probability assessment would have been. Politicians usually don’t talk in probability terms; they usually treat the most likely outcome as if it were the the certain outcome, which leads to lots of mistakes. Perhaps Sen. Obama should have been less dogmatic about his assessment.
But assume for the moment that the Surge was a good bet, rather than a bad one, ex ante, in terms of its ability to contribute to the restoration of order in Iraq. Does that prove that it was a good idea? By no means.
To know that, you would have to know not only the probabilities but the stakes. Was the gain from a successful Surge three times as great as the loss from an unsuccessful Surge? If so, taking a one-in-four shot might have been justified. And of course there’s always the counterfactual question: had we not “surged,” how much of the improvement in Iraq would have happened anyway?
In addition, we need to ask about the costs of the Surge, in particular the opportunity cost. The troops that went to Iraq couldn’t be sent to Afghanistan instead, and the deterioration in the situation there (and across the border in the Northwest Frontier Province of Pakistan — has been as dramatic as the improvement in Iraq. And the Pentagon has made it clear that there’s a trade-off: more troops for Afghanistan must mean fewer troops for Iraq. Would we be safer today if we’d “surged” in Afghanistan instead of Iraq? It’s hard to know.
Obama’s consistent position since before the Iraq war started that Afghanistan, from which the 9/11 attack was directed, and not Iraq, is the central front in our battle with al-Qaeda. From that perspective, the costs of the Surge may well have exceeded the benefit, even though the Surge itself was surprisingly successful.