Top US generals told lawmakers at a congressional hearing that America lost the Afghanistan war and that it was caused by miscalculations spanning several administrations and the August collapse of the erstwhile government in Kabul could be traced to the 2020 agreement with the Taliban.

“It wasn’t lost in the last 20 days or even 20 months. There’s a cumulative effect to a series of strategic decisions that go way back,” chairman of the joint chiefs of staff General Mark Milley told the armed services committee of the House of Representatives, on Wednesday.

“Strategically, the war is lost – the enemy is in Kabul,” he went to say, referring to the Taliban taking power in Kabul.

General Milley cited several reasons that he said needed to be looked at such as the decision to shift forces from Afghanistan for the war in Iraq and the failure to “effectively deal with Pakistan”, where many of figures sought by US-led coalition forces sound shelter.

General Milley had spoken of the Pakistan’s sanctuaries also at an Afghanistan hearing in the US senate, and called for a need to review Islamabad’s behaviour. Secretary of state Antony Blinken had earlier said ties with Pakistan were under review because of its duplicitous role in Afghanistan, where, he added, it had been “hedging its bets”.

General Frank McKenzie, the head of the US Central Command that ran the war in Afghanistan, told lawmakers that the rapid collapse of President Ashraf Ghani’s government in Kabul, which had caught the US completely unprepared, could be traced to the agreement that the Trump administration had signed with the Taliban in Doha in February 2020.

“The signing of the Doha agreement had a really pernicious effect on the government of Afghanistan and on its military – psychological more than anything else, but we set a date certain for when we were going to leave and when they could expect all assistance to end,” General McKenzie said.

The Trump administration had kept the Ashraf Ghani government completely out of the agreement, which had set a timeline for the US and international forces to leave Afghanistan by May 1 of 2021, based on some conditions, which the generals also told the lawmakers, were largely not unfulfilled with one exception that the Taliban will not attack US or coalition forces.

Defence secretary Lloyd Austin testified alongside Milley and Mckenzie and generally agreed with the generals’ assessments of the way the Afghanistan war unfolded over 20 days and how it ended. The three officials had earlier told the US senate that they had recommended to the president that the US should retain 2,5000 personnel in Afghanistan, contradicting Biden, who had claimed he did not get that advice.

Mckenzie further said that cutting troops to below 2,500 “was the other, sort of, nail in the coffin”. “It has been my position in my judgement, that if we went below an advisory level of 2,500, I believe that the government of Afghanistan would likely collapse and that the military would follow; one might go before the other but I believe that was going to be the inevitable result of drawing down to zero and I’ve expressed that opinion writing for quite a while now,” said the top US general for the Afghanistan war.