President Joe Biden announced Wednesday it's "time to end" America's longest war with the unconditional withdrawal of troops from Afghanistan where they have spent two decades in a bloody, largely fruitless battle against the Taliban.
Dubbed the "forever war," the US military onslaught in Afghanistan began in response to the September 11, 2001 terrorist attacks against the United States.
Now, 20 years later -- after almost 2,400 US military and tens of thousands of Afghan deaths -- Biden is naming September 11 as the deadline by which the last US soldiers will have finally departed.
The war is at best at a stalemate.
The internationally backed government in Kabul has only tenuous control in swaths of the country, while the Taliban are growing in strength, with many predicting the insurgency will seek to regain total power once the government's US military umbrella is removed.
In a speech later Wednesday, Biden was to tell Americans that it's time to accept the reality that there's no alternative to a clean break.
"We cannot continue the cycle of extending or expanding our military presence in Afghanistan hoping to create the ideal conditions for our withdrawal, expecting a different result," he was to say, according to excerpts released ahead of his speech.
"I am now the fourth American president to preside over an American troop presence in Afghanistan. Two Republicans. Two Democrats," he said. "I will not pass this responsibility to a fifth."
Biden's decision is not a shock. The war is hugely unpopular among voters and Biden's predecessor Donald Trump had committed to an even earlier exit of May 1.
Biden ally Senator Bernie Sanders called it "brave."
However, there was immediate criticism from some quarters that the United States is abandoning the Afghan government and encouraging jihadist insurgencies.
"Wars don't end when one side abandons the fight," influential Republican Representative Liz Cheney said.
"Withdrawing our forces from Afghanistan by Sept 11 will only embolden the very jihadists who attacked our homeland on that day 20 years ago."
Biden was set to say in his speech that Washington will continue to support the Afghan government, only not "militarily."
This will mark a profound shift in clout for the beleaguered government and its US and coalition-trained security forces.
A senior administration official said the US military exit would be completed by September 11.
Biden had earlier considered stationing a residual US force to strike at Al-Qaeda or other international jihadist groups in Afghanistan or making withdrawal contingent on progress on the ground or in slow-moving peace talks.
In the end, he decided to leave only personnel to guard installations like the US embassy in Kabul, a senior official said.
"The president has judged that a conditions-based approach, which has been the approach of the past two decades, is a recipe for staying in Afghanistan forever," the official told reporters on condition of anonymity.
US Secretary of State Antony Blinken said the moment had arrived to bring forces back home, and Washington would work out a "coordinated" withdrawal plan with its NATO allies.
"Together, we have achieved the goals that we set out to achieve and now it is time to bring our forces home," Blinken said ahead of talks with NATO partners in Brussels.
German Defence Minister Annegret Kramp-Karrenbauer said Wednesday that NATO would likely join the US in withdrawing its troops by September.
The Times newspaper said Britain would withdraw its roughly 750 troops, citing sources as saying "they would struggle without American support because of a reliance on US bases and infrastructure."
The Biden official said the withdrawal would begin in May and that the delay was largely logistical, with troops possibly out of Afghanistan well before September 11.
The official warned the Taliban -- who are observing a truce with US but not with Afghan forces -- not to strike coalition forces as they leave, saying that in response to any attack "we will hit back hard."
But a threat assessment report published Tuesday by the director of US national intelligence said the Taliban "is confident it can achieve military victory."
The upheaval raises big questions over the future of attempts to modernize Afghanistan, especially for Afghan women who have benefited from increased rights, like access to education.
The Taliban, who enforce an austere brand of Sunni Islam, banned women from schools, offices, music and most of daily life during their 1996-2001 rule over much of Afghanistan. Two decades later, 40 per cent of schoolchildren are girls.
Biden's decision came as Turkey said it will host a US-backed peace conference from April 24 to May 4 that would bring together the Afghan government, the Taliban and international partners.
But Mohammad Naeem, spokesman for the Taliban office in Qatar, said the insurgents will not participate in any conference on Afghanistan's future "until all foreign forces completely withdraw."
A decade ago, the United States had about 100,000 troops in Afghanistan.
The troop figure by the end of Trump's presidency had gone down to 2,500. As of February this year, NATO had around 10,000 troops in Afghanistan.