Leading article: Afghanistan - enough is enough - Leading Articles - Opinion - The Independent Would Afghanistan be worse off today if British forces had withdrawn from combat roles in 2010, as this newspaper proposed on Remembrance Sunday the year before? This is an unanswerable question, but if there are reasons for thinking that the consequences would have been negative, why should they be any less so at the end of 2014, when American and British forces intend to pull out? The official answer is that another three years will give time for the Afghan security forces to be built up so that they can assume responsibility. That has been the official line for the past 10 years - it has always been claimed that, in another few years, the Afghans will be ready to take control of their own country. The Independent on Sunday has reported more than once the despairing secret assessments of Afghan capability carried out by the International Security Assistance Force (Isaf). There has been no observable progress for years. There are two possible responses to this. One is to say, give us more time and we can fix it. That is the definition of madness: to repeat actions and to expect a different result. The alternative response would be to say, "We are leaving in a year, you must be as ready as possible by then." It could be argued that only the setting of a withdrawal date will concentrate minds. But once that decision has been made, the date might as well be in a year's time. Little or nothing will be gained by taking longer over it. Jim Murphy, Labour's defence spokesman, took issue with our view in The Independent on Sunday last week, saying that he agreed with the timetable set by the coalition government, in approximate co-ordination with Barack Obama's administration. "Early withdrawal would be as dangerous as a 'cliff-edge' departure, which could threaten the nation's fragile fortunes," he wrote. But what we proposed was neither early - Isaf has been in Afghanistan for a decade now - nor sudden. A more substantial criticism might be that a unilateral British pull-out would undermine our American partners. After all, we have 9,500 troops there, while the US has 90,000. This is not a trivial consideration, but neither should it be the determinant of British foreign policy. This newspaper is not opposed to the use of British military force in a just cause. We supported the limited intervention in Libya last year. Again, nothing is certain, but it averted a bloodbath that Gaddafi had threatened in explicit terms and, whatever difficulties that country may now be going through, the Libyans are more the authors of their destiny than the unfortunate Iraqis ever were. We should, however, be clear about the conditions in which intervention is justified. At the moment, those conditions are not unambiguously satisfied in Syria, horrible though the war might be that Bashar al-Assad is fighting against his own people. No one has yet come up with a plan for no-fly zones or arming the opposition that offers any certainty of protecting more people than it would harm. But we agree with Senator John McCain about this much: that Nato countries should be planning for military contingencies. Although our mission in Afghanistan did not fit into the emerging doctrine of liberal intervention - it was not to avert a humanitarian emergency - we supported it in the early phase, to require the Taliban to comply with international law by surrendering the perpetrators of 9/11. For noble but misguided reasons, the mission then crept, quite quickly, towards the construction of a new country. But, as Mr Murphy wrote last week, it should never have been "about nation-building, but about preventing Afghanistan from again becoming an incubator for extremism." That objective was achieved early on, and the country appeared unlikely to fall again under the sway of the Taliban. Paradoxically, it is the presence of foreign troops in Afghanistan that now gives the Taliban more power and coherence. Perfect conditions for withdrawal are never going to be achieved in Afghanistan, any more than they were in Iraq. And we have long since passed the moment when the benefits of staying longer outweigh the costs. Since November 2010, when the IoS wanted the last British combat troops to be withdrawn, 61 British soldiers have lost their lives, including six in the explosion last week. The sooner we say, "Enough is enough," the better.