Those who say Iraq can't be compared to Vietnam are right. As John Gray, professor of European thought at the London School of Economics, writes in the Guardian, Vietnam pales in comparison to the mess George w. Bush has crafted in Iraq:
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.
What the world needs from western governments is not another nonsensical crusade. It is a dose of realism and a little humility.