... This is not the first time that a U.S. military intervention has produced a debacle, and the tragic fate of South Vietnam is far from the sole precedent. The history of Central America and the Caribbean offers numerous others. In Guatemala in the 1950s and 1960s, a U.S.-backed regime change was the prelude to a protracted civil war that claimed hundreds of thousands of lives.

By any meaningful definition, a similar process is now underway in Iraq. According to the unofficial Iraq Body Count, more than 47,000 civilians have been reported killed since the U.S. invasion; on the basis of household surveys, however, the Lancet recently estimated deaths due to violence at 600,000. A rising proportion of this violence is sectarian in character. There were ten times as many sectarian attacks in July as in January.

The cycle of sectarian violence is already well-established in the capital, despite recent U.S. efforts to "clear and hold" trouble spots. In the last two months, however, the killing has spread centrifugally into neighboring provinces, leading to bloodbaths in places like Duluiyah, a predominantly Sunni town north of Baghdad, and Balad, a neighboring Shia enclave. There also has been an upsurge of violence between Kurds and Arabs in Kirkuk. American dreams of devolving responsibility for security to the country's own army and police forces are becoming nightmares. Elements in these same forces are among the most flagrant perpetrators of ethnic cleansing.

History strongly suggests that, once such internecine warfare gets underway, it is extremely hard to stop without external intervention. Violence begets more violence. Vendettas poison relations between neighbors. Though low-intensity conflict can continue inconclusively for decades (think of Sri Lanka), it is also possible for the killing to increase exponentially (Bosnia, Rwanda) until large-scale ethnic cleansing has created homogeneous statelets.

Quite apart from the economic effects of this crisis--higher oil prices, slower growth--the international political consequences are bad and getting worse. The deterioration of Iraq may well be increasing the risk of terrorist attacks on the United States itself, according to leaked details of the latest National Intelligence Estimate. At the same time, this screwup has brought the United States into greater international disrepute than at any time in its history, reducing its ability to deal with other threats and crises.

This is a truly calamitous state of affairs. The big problem is that few, if any, of the options reportedly being considered by the Baker-Hamilton Commission offer credible solutions. Any timetable for U.S. withdrawal will merely reward the men of violence. Any political decentralization will merely accelerate the country's bloody disintegration. Most attention therefore has focused on Baker's anticipated "realism" with respect to third parties, specifically Syria and Iran. Dialogue with these former pariahs, he has hinted, may help to stabilize Iraq. But, if this is the best he can come up with, he should have stuck to dimpled chads. From a truly realist perspective, both of those notorious sponsors of terrorism have a clear interest in exploiting America's weakness. Opening channels to Damascus and Tehran will bring little joy to Washington--and much humiliation.

So, are there any other options? Or must we brace ourselves for helicopters airlifting the last Americans from the Green Zone and the bloody breakup of Iraq? I can think of only three possibilities. The first is simply to start paying Iraqis to disarm and seek peaceful employment. It has become conventional wisdom that the U.S. presence in Iraq is disastrously expensive. Joseph Stiglitz, the Nobel-winning economist, forecasts a total cost of between $1 and $2 trillion, depending on whether the U.S. presence in Iraq ends in 2010 or 2015. Such numbers sound terrifying-- although, as an annual expenditure in relation to gross domestic product (1.1 percent at most), this still remains a comparatively cheap war. The real problem has been twofold. First, a large fraction of the money spent has gone to supplying U.S. troops. Second, far too much of the money earmarked for economic reconstruction has been pocketed by poorly monitored contractors. The result has been a kind of reverse Marshall Plan, in which U.S. money has gone to ... Americans. As a result, instead of economic recovery helping to embed democracy, economic stagnation has fueled civil war. Yet, with a fraction of the money that goes to our boys' cheeseburgers, you could buy and decommission all the AK-47s in Iraq.

Step two would be to implement what might be called a British-style strategy, in the spirit of Gertrude Bell. Leave Prime Minister Nuri Al Maliki be. Concentrate instead on buying the support of tribal sheiks. Point to the most prosperous Arab countries in the region--all of which are monarchies--and ask the sheiks how much richer and happier they all would be if the Hashemites had not been overthrown in 1958.

Step three is the most important: Ignore the Syrians and the Iranians and focus instead on (a) the permanent members of the Security Council, (b) the Germans, and (c) the Japanese. All--with the exception of Russia--stand to lose economically if Iraq spirals into the abyss. True, the internationalization of conflict zones cannot turn sows' ears into silk purses. But Sarajevo today is better than Sarajevo ten years ago....