Afghanistan exit strategy in doubt as Isaf command bans joint operations Nato's exit strategy in Afghanistan appeared to be in serious jeopardy on Tuesday, after it emerged that the US military command had set fresh limits on joint operations with Afghan troops in the wake of a rapid increase of "green-on-blue attacks" involving local soldiers turning their guns on their foreign mentors. The order, issued by the deputy commander of the Nato-led International Security Assistance Force (Isaf), Lieutenant General James Terry, indefinitely suspends joint patrols and other operations for units smaller than 800-strong battalions. British and Nato officials sought to play down the impact of the measures, emphasising that they were intended to be temporary. But experts said the most effective mentoring took place in small units, warning that the decision would undermine Nato's training role and further unravel the already precarious trust between Afghans and their western allies. The Nato withdrawal from routine patrols means that Afghans could be left without potentially life-saving mine detectors and other equipment. Nato's plan to withdraw combat troops by 2014 depends on Afghan security forces being able to keep the Taliban at bay without assistance, an increasingly daunting goal. "The cessation of the partnership is likely to seriously damage the mission," said Paul Quinn-Judge, the acting Asia director of the International Crisis Group. Things are already looking bad for 2014, with both the [troop] drawdown and possibly some very messy elections. The partnership was in many ways the core of the mission - 2014 could turn out to be even tougher without it. Adding to the air of confusion surrounding the Afghan mission, the announcement appeared to take the Americans' allies, including Britain, by surprise. The British defence secretary, Philip Hammond, had told the House of Commons on Monday that attacks by Afghan soldiers on their trainers and mentors, known as "green-on-blue" attacks, would not change policy. "We cannot and we will not allow the process to be derailed," he had said. The Kabul government also gave the impression it had been caught unawares. The president's office did not respond to requests for comment and the defence ministry simply dismissed reports of the policy change as "incorrect." British defence officials did not hide their anger on Tuesdayat the manner in which the change had been announced. Summoned back to parliament, Hammond played down the importance of the change, calling it tactical rather than strategic and blamed "overexcited" reporting of the announcement. The minister also claimed that it would have limited effect because US troops, the biggest Isaf contingent by far, did not mentor small units. "We try to get closer to the people, we try to get lower down the command structures and we try to be more embedded than sometimes the Americans appear to do," the defence secretary said. US and Nato sources queried Hammond's description of the American role, pointing out that before the weekend policy announcement, American troops routinely patrolled and shared outposts with small Afghan units. Pentagon officials said many joint operations with Afghan troops, including patrols and combat, involve small squads of about 10 US soldiers or platoons of up to 40. Colonel Thomas Collins of Isaf said he could not quantify the number of joint operations but confirmed that they did involve forces below battalion level. "We partner with Afghan security forces at all levels of command and in every regional command here for general security operations," he said. It is extensive. The number of "insider attacks" by Afghan soldiers and police officers has surged recently. There have been 36 green-on-blue attacks this year, killing 51 Nato soldiers. The increase in the number of killings has divided the Nato allies over how to respond. It is not a sensible decision. We have blinked," a source familiar with the Isaf mission in Afghanistan said of the new new measures. There is no co-ordinated Taliban 'strategy' for these attacks. A majority of the attacks are not in pursuit of some lofty Taliban or fundamentalist goal, but more as a result of local disputes, grudges etc. By ceasing lower-level co-operation, for however long, you are lending credence to the myth that green-on-blue is some kind of hugely well-orchestrated operation, which it isn't. The source asked: "And what happens when you re-commence lower-level collaboration? You haven't addressed the causes - it's almost impossible to do so - so there will be further green-on-blue incidents, certainly. You are just setting yourself up for failure in the public's eyes. Shashank Joshi, a research fellow at the Royal United Services Institute, said: "This is a symbol of a much deeper problem of Afghan-American distrust. In a way, there was a bigger change last month when special forces stopped training [new] Afghan local Police. This is a signal that the US does not trust its counterparts. It is a statement of mounting cynicism and resignation. After earlier insider attacks, the Afghan president, Hamid Karzai, had pledged to vet all new recruits but Nato officials on Tuesdaysaid the plan had never been properly implemented. "Vetting is virtually impossible in a place like Afghanistan," said Colonel Richard Kemp, a former commander of British forces in Afghanistan. In such conditions the suspension of joint patrols made "eminent sense" but he said much would depend on how long the suspension lasted. You can't just allow these attacks to carry on. You have to do something," Kemp said. The acute political sensitivities surrounding the affair was reflected in a special communique issued later on Tuesday by the US embassy in London, which declared that Isaf remained "absolutely committed" to training and advising Afghan forces. Growing political opposition to Britain's continuing military presence in Afghanistan was reflected by interventions in the Commons from both government and opposition benches. John Baron, a Conservative MP and former army captain, whose urgent question forced Hammond to come to the Commons, said that the new Isaf order threatened "to blow a hole in our stated exit strategy, which is heavily reliant on these joint operations continuing."