Boris Johnson has faced a barrage of criticism from MPs over the UK’s role in Afghanistan, in an emergency House of Commons debate on the crisis.
His predecessor as PM Theresa May said it was “incomprehensible” the UK was not doing more to maintain a presence, while ex-minister Johnny Mercer demanded more help for veterans.
Labour leader Sir Keir Starmer accused Mr Johnson of “staggering complacency”.
But Mr Johnson argued Nato’s “core mission” in Afghanistan had succeeded.
Addressing a packed Commons, he said the country had been largely cleared of al-Qaeda terrorists, while the population had enjoyed better education, women’s rights and free elections since the 2001 invasion.
But Conservative MP Tom Tugendhat, who chairs the Commons defence committee and himself served in Afghanistan, said it had been “shameful” of US President Joe Biden to question the willingness of the US-trained Afghan army to fight the Taliban.
And, in an emotional speech that was listened to in silence, he told of grief and rage felt by veterans at the “abandonment” of Afghanistan.
The UK has agreed to resettle up to 20,000 Afghan refugees displaced by the return of the Taliban over the next few years.
Efforts are also continuing to evacuate UK nationals from Kabul airport, but Downing Street did not deny a report that one plane had taken off “almost empty”.
Parliament was recalled from its summer break for the debate on the situation in Afghanistan.
Mrs May called Nato’s withdrawal “a major setback for British foreign policy”.
She said it was “incomprehensible and worrying” that the UK government had not been able to put together an “alternative alliance of countries” to continue to support the Afghan government in the absence of US forces.
Another Conservative MP and former soldier, foreign affairs committee chairman Tobias Ellwood, argued the UK “should never have left” Afghanistan.
“What we require is the backbone, the courage, the leadership to step forward, yet when our moment comes such as this we are found wanting,” he said.
Mr Mercer, who served in Afghanistan and who quit as veterans’ minister earlier this year, accused Mr Johnson of “consistently failing” to support ex-soldiers.
In normal times, opinion on the green benches of the Commons chamber can crystallise during a debate.
A minister’s credibility can evaporate, MPs can spot the bloom of sweat on a beleaguered brow, dissidents can discover others agree with them, and the noise level ramps up as a political herd instinct kicks in.
It’s called the “mood of the House” and under pandemic restrictions it disappeared.
For more than a year, ministers in trouble faced a mostly empty chamber, and fielded the attacks of MPs who were called in a pre-determined order, heading off unexpected attacks.
The pressure levels needed to crystallise opinion were never reached.
All that changed today, as the cap on the number of MPs allowed into the chamber was lifted and the benches were once again packed.
The PM faced non-stop interventions (mostly critical, some hostile) in his speech, and, worse, he could hear attacks on his handling of Afghanistan delivered with minimal rumbles of disagreement from his own side.
It has been a damaging day for ministers who have perhaps become too used to the protection the pandemic restrictions gave them.
Some 457 UK personnel have died and more than 2,000 have been wounded in the Afghanistan conflict, prompted by the 11 September 2001 attacks on the US by al-Qaeda.
Mr Johnson said that “in spite of all the difficulties and challenges we knew we would face… we succeeded in that core mission” of removing the terror group’s operatives from Afghanistan.
“It would be fair to say [recent] events in Afghanistan have unfolded and the collapse [of the Afghan government] has been faster than even the Taliban themselves predicated,” he said.
“What is not true is to say the UK government was unprepared or did not foresee this.”
Mr Johnson said the Taliban, who have promised to observe human rights, must be judged on “actions rather than words”.
“At this bleak turning point we must help the people of Afghanistan determine the best of all possible futures,” he added.
But opposition leader Sir Keir Starmer accused the prime minister of “staggering complacency” and “appalling” judgement by failing to plan properly for the withdrawal of troops over the past 18 months.
He called the government’s refugee repatriation target too small and claimed the 20,000 figure had been “plucked out of the air”.
To jeers from Conservative MPs, he said: “The prime minister’s response to the Taliban arriving at the gates of Kabul was to go on holiday.”
SNP Westminster leader Ian Blackford argued that the future of Afghanistan had “never been so uncertain” and that refugees needed more help.
Liberal Democrat leader Sir Ed Davey branded the prime minister a “national liability” who could not “escape culpability for this disaster”.