For much of the last five years I have been writing about the buildup to the Iraq war, the management of the war, and the war’s likely consequences. Apart from this article in the Atlantic a year and a half ago, I have avoided writing or saying much about what the United States should do next in Iraq. About the general management of the “war on terror” — sure, no problem, as shown in one article from early in 2005 and another from a few months ago. But as for the “best” way to deal with the worst strategic error in modern American history, I’ve had nothing useful to say.

There was a natural but not so high-minded reason I felt this way. Having been against this venture from the start, I had no stomach for coming up with “solutions” to problems that I thought ahead of time were likely to prove insoluble. (Example one: maintaining U.S. presence long enough to ensure public order, and thereby let the economy recover and the institutions of civil society emerge — despite the certainty that a non-Islamic, non-Arabic speaking force of armed foreigners would be seen as “occupiers” rather than as “liberators” within weeks. Example two: finding a way for Iraq’s disparate groups to resolve their arguments and go on as one unified state, absent the oppressive strong-man figures who previously had held the country together.) Such tasks would have been difficult — in my view, essentially impossible — in the best of circumstances. We’ll never know whether that pessimistic view was correct, because the circumstances of the occupation, far from being the best, were just about the worst.

There was another reason, too. The question “what do we do now?” implies that the answer will in some way be “useful.” For the last six months at least I have not thought that any available answer was good. But when I was on a book tour this fall, I couldn’t get away just with saying that. So I made a point about which I am changing my mind.

My previous point had been: this war was a bad idea, carried out with near-criminal incompetence and irresponsibility. But — I said — even those who opposed the war could not pretend that the last three and a half years had not occurred. The entire United States, including critics of the war, had taken on a responsibility not to make things even worse for the people of Iraq. And as long as the evidence suggested that conditions would become even worse for civilians — that the car bombings would increase, the ethnic cleansing would grow more brutal, and everyone would have as much reason to curse the United States for the way it left as for the way it came in — we could not “just leave.”

Moreover, by undertaking this ill-considered war, the United States had made itself hostage to Iraq in two important strategic ways. If it “lost” Iraq and its mighty military were driven out, this would be seen worldwide as a humiliation, comparable to what the old Soviet Union underwent in Afghanistan and what the U.S. suffered in Vietnam. I was against the Vietnam war, too, but no one can deny that for two decades at least the fall of Saigon was equated worldwide with America’s “defeat.” And (strategic reason number two), while Al Qaeda-style terrorists had not been based in Iraq before the invasion, they certainly were there now. The existence of Afghanistan as a terrorist haven before 2001 was a problem for America, and that is the role that the Sunni parts of Iraq might play after the U.S. left.

For those reasons, I said, the United States needed to do everything it could to find a way to leave “decently.” Mainly this meant shoring up Iraq’s own security forces so they could maintain a semblance of order for a “decent interval” after we left. (Note to the young: “decent interval” was the cynical term for how long a South Vietnamese regime would have to survive after American withdrawal, in order for the U.S. to have left with “honor.”) Otherwise, I thought and said as recently as two months ago, it would be irresponsible just to go.

The findings of the Baker-Hamilton Iraq Study Group, as related through obviously authoritative leaks, mark a shift in the debate — and a change in my mind. This is not because the group has come up with a “good” idea where everyone else has failed. (To be fair, its ideas don’t seem worse than anyone else’s either — and they usefully straddle the divide between “cut and run” and “stay the course” by saying that the troops have to leave, but without saying exactly what the timetable is.) Rather it is because of the implied conclusion on which the panel’s findings (as reported) are based: that things are not going to get better, and the time for cutting losses has come.

This of course is entirely contrary to the Bush Administration’s position, which as of the president’s latest statement today still asserted that American troops must stay until “the job is done.” It’s at odds with many liberal hawks, and conservative hawks too, who say that the U.S. “can’t afford to lose” so must stay until we “win,” whatever that means. In fact, “winning” now amounts to some combination of: (a) leaving without appearing to be chased out; (b) leaving without an immediate upsurge in violence; and (c) leaving without al Qaeda-etc trainers quickly filling the vacuum, especially in the Sunni regions. Yes, we can’t afford any of those consequences of losing. But — because of misjudgment, mismanagement, and failures we will be ruing for years — they appear to be what’s in store.

If it is not in our power to prevent these disasters, then it is better to do as little extra damage to ourselves as possible before they occur. Sure, it is theoretically in our power to do more in Iraq. It’s just not possible in the real world. To start with: we’re not going to double the size of our military to sustain an open-ended presence in Iraq.

So the choice is between a terrible decision and one that is even worse. The terrible decision is just to begin leaving, knowing that even more innocent civilians will be killed and that we’ll be dealing with agitation out of Iraq for years to come. The worse decision would be to wait another year, or two, or three and then take that terrible course. If we thought a longer commitment and presence would lead to a better outcome, then the extra commitment might be sensible. But nothing occurring in Iraq in the last year has given rise to any hope that things are getting better rather than worse. (This, by the way, is the reason I have changed my mind: the absence of evidence that the chances for a “decent” departure will improve.)

So maybe the Study Group is made of geniuses after all. Begin leaving, as they (will) recommend. Don’t say exactly when you’re going (what’s the point?). Do as much as you can with the other regional powers to minimize the ripple-effect damage. And, as the study does not say, recognize that the United States has inflicted grave harm, including on itself.