Leading article: A decade at war is long enough

A decade at war is enough, said Stephen Harper, the Canadian prime minister, three years ago. This year he carried out his promise to pull Canadian forces back from combat in Afghanistan and to restrict them to training Afghan forces. From a peak of 2,800, there are now only 520 Canadian troops in the country.

Two years ago, this newspaper proposed something similar for the British mission: that it should end its combat role except for special forces, and that it shouldsupport Afghan forces away from the battlefield.

Last year, when he became Prime Minister, David Cameron broke the taboo on deadlines and set one for the British withdrawal. It was later than The Independent on Sunday would have wanted, but it ended the fiction that the timetable would be dictated by the securing of unrealisable objectives. And there was some political advantage in synchronising the British pull-out with the American one, even if the Canadians had shown that the sky would not fall in if some allies pulled out at different times.

As we report today, there was some grumbling within the British top brass at Mr Cameron's temerity in taking political decisions. As we say, our only complaint is that the Prime Minister did not set an earlier date for the British withdrawal. To the extent that he asserted political control of the military, he is to be congratulated. For too long, the British engagement in Afghanistan has been run by a short-term and short-sighted military, which has involved "mowing the grass" of the Taliban insurgency in different provinces every few years.

At some point, someone had to stand back and say, "a decade at war is enough". The original military intervention in 2001 – toremove the Taliban government and to prevent it harbouring al-Qa'ida – was justified. The subsequent intention to help the Afghan people achieve a basic level of security and political stability was also right, both in itself and in our self-interest, because to have allowed the country to lapse into disorder would have been to negate the effect of the intervention.

However, by a process familiar to history, that of the ratchet, the Nato mission in Afghanistan grew, with civilian agencies wanting the military to help them build a nation, while the military was always confident that just one more push would defeat the enemy. At some point Nato's leaders had to recognise that an open-ended commitment serves no one's interest. The Afghan government is weak and corrupt, but western military force will not make it strong and honest in the long run – except by pulling out.

Although President Obama split the difference by deciding in December 2009 both to increase US troop deployment to Afghanistan and to set a deadline for withdrawal, by the second decision he finally asserted political authority over the mission. So, the 90,000 US troops and 9,500 British ones are now to be withdrawn from combat roles by the end of 2014. The White House confirmed on Friday that the President still intends to withdraw 33,000 troops next year.

This is despite the lack of progress in starting official talks between the Afghan government and the Taliban. After the murder last month of Burhanuddin Rabbani, a former Afghan president charged with opening negotiations, Hamid Karzai, the current president, announced yesterday that he was abandoning attempts to talk to the Taliban. It was not possible to find Mullah Omar, its leader, he said. "Where is he? We cannot find the Taliban Council. Where is it? Who is the other side in the peace process? I do not have any other answer but to say Pakistan is the other side in the peace talks with us."

He has a point. But the logic of that – and of the killing of Osama bin Laden in Abbottabad – is that Nato's attention should be focused as much on Pakistan as it is on Afghanistan. That means starting again from first principles, andaccepting that perfect solutions are not possible. The Afghan security services are in a poor state, but another 10 years of the same is not necessarily going to change that. Our aim ought to be to contain the Taliban, not to eliminate them totally, and to try to prevent Pakistan sliding further in a dangerous direction.

A decade at war is long enough.