IRAQ ES CUESTIÓN de números y de tiempo, escribió Niall Ferguson hace poco más de un mes en un estupendo artículo que, además, es una muestra impecable de cómo hacer una crítica constructiva a la estrategia yanqui:

"I think that this could still fail." Those words - uttered by a senior American officer in Baghdad last month - probably gave opponents of the war in Iraq a bit of a kick. Judging by the polls, a majority of Americans probably now share that view. According to Gallup, 57 percent of Americans say it was not worth going to war in the first place. Around the same percentage say things are going badly today.

Yet history strongly suggests that an American withdrawal from Iraq in the near future would be a disaster. As another U.S. officer told The New York Times recently: "If we let go of the insurgency ... then this country could fail and go back into civil war and chaos."

People in Lebanon need no reminder that failed American interventions can leave "civil war and chaos" in their wake. But what happened in Beirut in 1983 is part of a pattern going back to Vietnam and Cambodia in the 1970s, and forward to Haiti in the 1990s. To talk glibly of "finding a way out of Iraq," as if it were just a matter of hailing a cab and heading for Baghdad airport, is to underestimate the danger of a bloody internecine war after the American exit.

Already, a substantial section of the Sunni minority in Iraq is engaged in a campaign of violence designed to prevent a stable majoritarian regime from emerging. The Shiites are preparing to defend their newfound political power by force of arms. Meanwhile, many young Kurds are preparing to fight a war of independence. Indeed, it is not too much to say that civil war in Iraq has already begun, since the majority of people killed in this year's bombings have been Iraqis, not Americans.

Instead of throwing up their hands in an irresponsible fit of despair, Americans need to learn from the past: not just from their other premature departures, but also from earlier victories over insurgencies. For not all insurgencies are successful. Indeed, of all the attempts in the past century by irregular indigenous forces to expel regular foreign forces, around a third have failed.

Leed lo que sigue, que es donde está la chicha.