"Everybody got it wrong" on how quickly the Taliban would take over Afghanistan, the head of Britain's armed forces has said.
Gen Sir Nick Carter told the BBC: "It was the pace of it that surprised us and I don't think we realised quite what the Taliban were up to."
Asked whether military intelligence was wrong, he said the government received intelligence from a variety of sources.
"It's not purely about military intelligence," he said.
The last British and US troops left Afghanistan a week ago, bringing their 20-year military campaign in the country to an end.
There has been criticism of the way the West withdrew from Afghanistan, with questions over how the Taliban was able to seize control of the country at such speed.
Foreign Secretary Dominic Raab told MPs last week the intelligence assessment had been that there would be a "steady deterioration" in the security situation in August but it was "unlikely Kabul would fall this year". However, the Taliban took over Kabul in mid-August.
Speaking to the BBC's Andrew Marr show on Sunday, Gen Sir Nick was asked how the predictions had been wrong.
"I think everybody got it wrong is the straight answer," he said. "Even the Taliban didn't expect things to change as quickly as they did."
The chief of defence staff said: "I don't think what anybody predicted was how fragile that Afghan government was and how fragile it was in relation to the command of its armed forces."
The Taliban is expected to announce a new government in the coming days, meaning foreign powers will have to adapt to the prospect of dealing with a Taliban administration.
https://www.bbc.co.uk/news/uk-58453258