The era of liberal interventionism in international affairs is over. Invading Iraq was always in part an oil grab. A strategic objective of the Bush administration was control of Iraqi oil, which forms a key portion of the Gulf reserves that are the lifeblood of global capitalism. Yet success in this exercise in geopolitics depended on stability after Saddam was gone, and here American thinking was befogged by illusions. Both the neoconservatives who launched the war and the many liberals who endorsed it in the US and Britain took it for granted that Iraq would remain intact.
As could be foreseen by anyone with a smattering of history, things have not turned out that way. The dissolution of Iraq is an unalterable fact, all too clear to those who have to cope on the ground, that is denied only in the White House and the fantasy world of the Green Zone. American-led regime change has created a failed state that no one has the power to rebuild. Yesterday's Oxfam report revealed that nearly one in three Iraqis is in need of emergency aid, and yet the anarchy that prevails prevents any such assistance.
Iraq now belongs in the history books, and Mesopotamia - the ancient region between the Tigris and Euphrates that includes parts of Turkey, Iran and Syria as well as the country that has been destroyed - is the site of an intensifying resource war. The Baghdad government is a battleground of sectarian forces while the Kurdish zone is independent in all but name. Utopian schemes for a federal state have been overtaken by an internal resource war fought out along sectarian lines.
Anarchy of this kind is a hideous condition in which to live, but its destructive impact reaches beyond the millions of Iraqis whose lives are already ruined. The surrounding states are being irresistibly drawn into the country's conflicts. Both Iran and Turkey have an interest in Iraq's oil wealth - Iran by virtue of having expanded its power and influence over the Shia majority, Turkey from fear that control of the oil-rich city of Kirkuk will pass into the hands of the Kurds. Such states can hardly avoid intervening and will not be deterred from acting to safeguard what they see as their vital national interests by threats from the Bush administration. Iraq is at risk of becoming the centre of a wider war, which the US can do very little to prevent - which shows up the lack of proportion in comparing the present conflict with Vietnam.
America was able to walk away from Vietnam because that country was peripheral in the world economy and the knock-on effects of US withdrawal were comparatively slight; Iraq, by contrast, is a key factor in global oil supplies, and if the US pulls out its ability to protect its allies in the region will be called into question. Another crucial difference is that Vietnam had an effective government in the north that could take over when the US exited. No such entity exists in Iraq. The feared domino effect in south-east Asia did not occur, but Iraq could be the scene of a domino effect in reverse in which the country's warring neighbours fall into the void left by the Americans' departure. By any standard, defeat in Iraq would be a more devastating blow to US power than Vietnam.
The most important - as well as most often neglected - feature of the conflict shaping up around Iraq is that the US no longer has the ability to mould events. Whatever it does, there will be decades of bloodshed in the region. Another large blunder - such as bombing Iran, as Dick Cheney seems to want, or launching military operations against Pakistan, as some in Washington appear to propose - would make matters even worse.
The chaos that has engulfed Iraq is only the start of a longer and larger upheaval, but it would be useful if we learned a few lessons from it. There is a stupefying cliche which says regime change went wrong because there was not enough thought about what to do after the invasion. The truth is that if there had been sufficient forethought the invasion would not have been launched. After the overthrow of Saddam - a secular despot in a European tradition that includes Lenin and Stalin - there was never any prospect of imposing a western type of government. Grotesque errors were made such as the disbanding of the Iraqi army, but they only accelerated a process of fragmentation that would have happened anyway. Forcible democratisation undid not only the regime but also the state.
Liberal interventionists who supported regime change as part of a global crusade for human rights overlooked the fact that the result of toppling tyranny in divided countries is usually civil war and ethnic cleansing. Equally they failed to perceive the rapidly dwindling leverage on events of the western powers that led the crusade. If anyone stands to gain long term it is Russia and China, which have stood patiently aside and now watch the upheaval with quiet satisfaction. Neoconservatives spurned stability in international relations and preached the virtues of creative destruction. Liberal internationalists declared history had entered a new stage in which pre-emptive war would be used to construct a new world order where democracy and peace thrived. The result of these delusions is what we see today: a world of rising authoritarian regimes and collapsed states no one knows how to govern.
Many will caution against throwing out the baby of humanitarian military intervention together with the neocon bathwater. No doubt the idea that western states can project their values by force of arms gives a sense of importance to those who believe it. It tells them they are still the chief actors on the world stage, the vanguard of human progress that embodies the meaning of history. But this liberal creed is a dangerous conceit if applied to today's intractable conflicts, where resource wars are entwined with wars of religion and western power is in retreat.
The liberal interventionism that took root in the aftermath of the cold war was never much more than a combination of post-imperial nostalgia with crackpot geopolitics. It was an absurd and repugnant mixture, and one whose passing there is no reason to regret. What the world needs from western governments is not another nonsensical crusade. It is a dose of realism and a little humility.
John Gray is professor of European thought at the London School of Economics and the author of Black Mass: Apocalyptic Religion and the Death of Utopia
© 2007 The Guardian