The fighting that has erupted in Basra should come as no surprise to anyone who has followed the course of the war in Iraq. While the US has spent the last year increasing force size in western Iraq and more aggressively challenging militias in Baghdad, the British have become more passive in Basra and have significantly reduced their footprint to one-tenth of their original commitment. That has made them almost invisible in the south, and since the Iraqi Army did not have a large enough presence there either, the British reduction allowed competing Shi’ite militias to take control of the area.

Now that the Iraqi government has enough troops, they have tried to make their writ run in Basra — and as the Times of London notes, that highlights the failure of the British in that area:

British forces, who can probably cobble together an armoured battle group of a few hundred soldiers, may well be asked to intervene should the Iraqi offensive fail. If that happens, any hope of the withdrawal promised by Gordon Brown last year of another 1,500 British troops this spring will have to be shelved until Basra can be stabilised.

It may even be necessary to reinforce the British contingent with more combat troops, something that the Ministry of Defence can ill afford as it prepares for the fighting season in Afghanistan.

The only other option would be for Britain to admit finally that it has lost the fight in southern Iraq. That would mean an ignominious withdrawal and handing over control of Basra to the Americans, who grudgingly would have to take over responsibility for the south. As American officers and officials have privately made clear, much of today’s problems in Basra can be traced back to Britain’s failure to commit the forces necessary to control Basra and southern Iraq in general.

Whereas President Bush’s “surge” tactic of sending 30,000 reinforcements to central Iraq has succeeded in bringing down the level of violence in Baghdad and Anbar province, the Americans believe that the gradual withdrawal of British troops from the south has had the opposite effect, a point that Mr al-Maliki and his soldiers are discovering to their cost on the streets of Basra today.

The British took the wrong tack in the south, and the results have been plain for at least two years. Instead of remaining in control of Basra and keeping order until Iraq could build their new security forces, their reduced footprint created a vacuum for order that the militias were only too happy to fill. The Sadr Mahdi Army and the Badr Brigades started seizing control of the streets in 2004, when the British reduced their forces to 8600 troops, and they have only strengthened their grip while the British retreated further. The Washington Post noted the problem last summer, as the surge began showing signs of ending the sectarian strife everywhere else.

The fighting in Basra now was inevitable at some point. Baghdad couldn’t allow a major city like Basra to operate outside its control forever. Instead of an orderly transition from Coalition to Iraqi security control, as is happening in the West, the Maliki government now has to take Basra by force — while the rump of British power sits in its bases, unable to contribute at all to security any longer. Whether Maliki decided to do this next week or next year, the fight in Basra had to happen at some point in order to apply the rule of law throughout Iraq.

That’s why this isn’t a collapse of the American surge, but a demonstration of the folly of premature withdrawal. The lack of fortitude on Iraq left a vacuum that created bigger problems and more serious fighting than tenacity did. Had we listened to the war’s critics in 2005 and 2006, gangsters would have swallowed the entirety of Iraq, and we would have a second Somalia in southwest Asia.