Donald Trump has announced on Twitter that he wants to bring all US troops home from Afghanistan by Christmas – a plan that came as a surprise to administration officials and which puts complicated peace negotiations in jeopardy. Multiple officials told the Associated Press they had not been informed of any such deadline and military experts said it would be impossible to withdraw all 5,000 US troops in Afghanistan and dismantle the US military headquarters by the end of the year. They suggested the president’s claim was aimed at shifting the news cycle away from coronavirus coverage and that the Pentagon would not act on the order before the 3 November US election. The announcement was, however, greeted enthusiastically by the Taliban on Thursday. If Trump follows through, the militant group would almost certainly claim it as a victory, after decades of couching their fight as a war against foreign aggression. “It’s no surprise that the Taliban have welcomed Trump’s announcement that he’d have the troops home by Christmas. They spent 19 years fighting for this,” said Ashley Jackson, the director of the ODI’s Centre for the Study of Armed Groups. “This is the last leverage the US had left in talks with the Taliban, and Trump is proposing to give it away for free.” Without the prospect of US military pressure, the Taliban would have little incentive to stay at the negotiating table with representatives of the Kabul government. From a practical point of view, disentangling a 19-year military presence would take considerably longer than two months. “It’s October, so no – it’s ridiculous. It’s simply can’t happen,” said Jason Dempsey, a former infantry officer who served in Afghanistan. “We could make some superficial show of pulling out uniformed troops, but obviously we still have a very massive contractor presence, and we would need a uniformed headquarters to oversee the shutdown and withdrawal of everything we have in country.” Trump has made impulsive policy announcements about Afghanistan on Twitter before, including calling off a US-Taliban summit last year, shortly before a withdrawal agreement was first expected to be signed. He also has a record of ordering abrupt and total troop withdrawals from foreign deployments. In most cases the Pentagon has sought to mitigate and slow the speed of the pullout but in some case the president has prevailed in bringing soldiers back home. The Afghan government and Taliban negotiators are currently attempting to hammer out a new political settlement for the country in the Qatari capital. The peace talks were set up under a withdrawal agreement signed earlier this year between the Taliban and Trump’s administration. The US-Taliban deal laid out a full departure of American forces by May 2021 but only if conditions on counter-terrorism were met, including severing ties with al-Qaida. Some critics of the Doha talks argue that the militants are merely marking time until the departure of US troops. Trump’s plans were announced in a tweet late on Wednesday night. The White House doubled down on the message on Thursday morning: “our troops in Afghanistan are coming home by the end of the year”, the official Twitter account for the administration said. It was the latest in a long line of ad hoc policy announcements from Trump that have caught his own advisers and military by surprise. His national security adviser, Robert O’Brien, had said shortly before Trump tweeted that troop numbers would be brought down to 2,500 early next year. About 4,500 troops are currently on the ground in Afghanistan, reduced from over 12,000 when the deal was signed in February. The Pentagon referred all requests for comment on Afghanistan drawdown plans to the White House. The Taliban welcomed Trump’s remarks as “a positive step towards the implementation of [the] Doha agreement”, a spokesman for the Islamist group, Mohammad Naeem, said in a statement, referring to the US withdrawal deal. Peace talks have been progressing slowly, with negotiators still trying to lay out the ground rules for their discussion. They are currently stalled on which school of Islam should be used when settling disputes. Trump has made a promise to “end” America’s wars overseas part of his bid for re-election this year, promising to bring troops home from a constellation of conflict zones including Iraq, Syria and Afghanistan. But past pledges to bring back troops have often been abandoned, reversed or only partially completed. After ordering a total withdrawal of US troops from Syria in October 2019, Trump was persuaded to let some stay on the grounds that they would protect oil installations there. A US military presence has remained, but it is about half the size of the thousand-strong force that was supporting Kurdish forces in northern Syria. In July, the Pentagon announced it was pulling nearly 12,000 troops out of Germany, after Trump called for a total withdrawal to punish the Berlin government over policy disagreements. Senior military officials made clear it would take years to redeploy that number of troops, and Congress is scrutinising the order. The drawdown of foreign deployed forces was dwarfed by the dispatch of 10,000 US troops to the Gulf following the killing of the Iranian general Qassem Suleimani in January. Dempsey, now adjunct senior fellow of the military, veterans and society program at the Center for a New American Security, said the Pentagon would wait to see the outcome of the presidential election before carrying out major troop movements. “I think the lesson we all should have learned after four years is the president’s conception of his powers doesn’t go anywhere beyond his enjoyment of having an expanded Twitter presence,” he said. “We’ve become so inured to these kind of kneejerk attempts to win the news cycle that nobody will be talking about this 48 hours from now.”