The Arithmetic of Failure

By PAUL KRUGMAN

Iraq is a lost cause. It’s just a matter of arithmetic: given the violence of the environment, with ethnic groups and rival militias at each other’s throats, American forces there are large enough to suffer terrible losses, but far too small to stabilize the country.

We’re so undermanned that we’re even losing our ability to influence events: earlier this week, Prime Minister Nuri Kamal al-Maliki brusquely rejected American efforts to set a timetable for reining in the militias.

Afghanistan, on the other hand, is a war we haven’t yet lost, and it’s just possible that a new commitment of forces there might turn things around.

The moral is clear — we need to get out of Iraq, not because we want to cut and run, but because our continuing presence is doing nothing but wasting American lives. And if we do free up our forces (and those of our British allies), we might still be able to save Afghanistan.

The classic analysis of the arithmetic of insurgencies is a 1995 article by James T. Quinlivan, an analyst at the Rand Corporation. “Force Requirements in Stability Operations,” published in Parameters, the journal of the U.S. Army War College, looked at the number of troops that peacekeeping forces have historically needed to maintain order and cope with insurgencies. Mr. Quinlivan’s comparisons suggested that even small countries might need large occupying forces.

Specifically, in some cases it was possible to stabilize countries with between 4 and 10 troops per 1,000 inhabitants. But examples like the British campaign against communist guerrillas in Malaya and the fight against the Irish Republican Army in Northern Ireland indicated that establishing order and stability in a difficult environment could require about 20 troops per 1,000 inhabitants.

The implication was clear: “Many countries are simply too big to be plausible candidates for stabilization by external forces,” Mr. Quinlivan wrote.

Maybe, just maybe, the invasion and occupation of Iraq could have been managed in such a way that a force the United States was actually capable of sending would have been enough to maintain order and stability. But that didn’t happen, and at this point Iraq is a cauldron of violence, far worse than Malaya or Ulster ever was. And that means that stabilizing Iraq would require a force of at least 20 troops per 1,000 Iraqis — that is, 500,000 soldiers and marines.

We don’t have that kind of force. The combined strength of the U.S. Army and Marine Corps is less than 700,000 — and the combination of America’s other commitments plus the need to rotate units home for retraining means that only a fraction of those forces can be deployed for stability operations at any given time. Even maintaining the forces we now have deployed in Iraq, which are less than a third as large as the Quinlivan analysis suggests is necessary, is slowly breaking the Army.

Meanwhile, what about Afghanistan?

Given the way the Bush administration relegated Afghanistan to sideshow status, it comes as something of a shock to realize that Afghanistan has a larger population than Iraq. If Afghanistan were in as bad shape as Iraq, stabilizing it would require at least 600,000 troops — an obvious impossibility.

However, things in Afghanistan aren’t yet as far gone as they are in Iraq, and it’s possible that a smaller force — one in that range of 4 to 10 per 1,000 that has been sufficient in some cases — might be enough to stabilize the situation. But right now, the forces trying to stabilize Afghanistan are absurdly small: we’re trying to provide security to 30 million people with a force of only 32,000 Western troops and 77,000 Afghan national forces.

If we stopped trying to do the impossible in Iraq, both we and the British would be able to put more troops in a place where they might still do some good. But we have to do something soon: the commander of NATO forces in Afghanistan says that most of the population will switch its allegiance to a resurgent Taliban unless things get better by this time next year.

It’s hard to believe that the world’s only superpower is on the verge of losing not just one but two wars. But the arithmetic of stability operations suggests that unless we give up our futile efforts in Iraq, we’re on track to do just that.