The UK wanted US troops to stay in Afghanistan, the head of the Armed Forces has revealed.
General Sir Nick Carter said President Biden's decision to pull out all 2,500 US troops by September 11 was "not the decision” the UK wanted.
The Chief of Defence Staff said: "It's not a decision that we'd hoped for. But we obviously respect it, and it's clearly an acknowledgement of an evolving US Strategic posture."
Earlier this week President Biden vowed to end America's "forever war" in Afghanistan, which began 20 years ago following 9/11, when they first arrived to bring down the Taliban regime harbouring Osama bin Laden.
Nato said the withdrawal process would begin by May 1 and could be completed in just a few months.
However, many have cautioned that the UK, which has agreed to an "orderly departure of our forces" by withdrawing the remaining 750 British troops by the deadline, said they had no choice but to cooperate because staying without the US was impossible.
Former defence minister Tobias Ellwood, Chairman of the Defence Select Committee, said the US decision risked "losing the peace" and allowing extremism to "regroup". It was "concerning" and "not the right move".
He said British forces had "no choice" but to leave due to the US's "significant force protection capabilities from which we benefited".
Mr Ellwood added: "Remaining allied forces are unable to fill that vacuum without upgrading our posture for which there is no political appetite."
There has also been concern that leaving Afghanistan without Nato military protection will result in civil war.
Ashraf Ghani, the President of Afghanistan, has claimed his government can endure the Taliban without the help of US troops, despite being heavily reliant on American support.
Earlier this year the US Treasury said the Taliban's notorious Haqqani network faction discussed forming a joint unit with al-Qaeda as the terrorist group gains strength in Afghanistan.
It added that the terrorist organisation continues to operate with the Taliban and is protected by the Afghan insurgent movement battling Mr Ghani's government, despite the Taliban agreeing to turn their backs on terrorism in return for an American troops withdrawal.
Sir Nick dismissed concerns, insisting that the Taliban has changed.
He told the Today programme: “There is a huge regard for women. There is a decent education system and there is a very vibrant media. And I actually think that the Taliban is not the organisation it once was.”
Sir Nick added: “It’s an organisation that has evolved significantly in the 20 years that we've been there. And I think they recognise that they need some political legitimacy and I would not be surprised if this scenario plays out that actually sees it not being quite as bad as perhaps some of the naysayers at the moment are predicting.”
However, Robert Clark, who served in Afghanistan, and is a defence fellow at the Henry Jackson Society said: “NATO forces still continue a much needed role not only in providing security, but by enabling and developing the Afghan National Army.”
Mr Clark added that once the US and British leave “in only five short months, the situation on the ground will unfortunately be dire, facing the beleaguered Afghan government, and the Afghan Security Forces”.
He added: “At present, NATO forces provide three battle winning capabilities - Intelligence, medical evacuation, and close air support. Without these, an emboldened Taliban and resurgent al-Qaeda and Islamic State will seize on this power vacuum in Kabul.”
Mr Clark said that “once again, it will be the Afghan citizens themselves who suffer”.
“The Taliban has already recently reaffirmed their insistence on strict sharia law, and their brutal system of local governance which the central government in Kabul will be powerless to stop in the wake of this premature NATO withdrawal.”