It wasn't only the West that found the speed of the Taliban's Afghan takeover surprising - the militant group was shocked too, an American diplomat has told Sky News.
The Taliban's fighters "outran the capabilities of their commanders", Ross Wilson said, speaking almost a year after the group took control of Kabul on 15 August 2021.
And they were successful because they "fought harder, longer and in a more determined manner than anybody else was prepared to do".
Mr Wilson, who served as the US's chargé d'affaires in Afghanistan between 2020 and 2021, said it was clear that change was coming in the run up to last summer's seismic events.
"From the beginning of June the situation gradually deteriorated," he said, noting that about 70-80 district capitals fell to Taliban control.
Then, at the beginning of August, "the first of a series of provincial capitals fell… initially out near the Iranian border in the west and then most alarmingly the cascading set of provincial capitals to the north of Kabul".
The US "did not anticipate the fall of the Afghan government in the middle of August or that it would be that rapid", Mr Wilson said, while the swift pace "also surprised the Taliban".
That was shown by the way "Taliban forces comported themselves", he went on, adding: "Assurance was given to us by Taliban leaders that their fighters would not in fact advance into Kabul itself, that they would stop.
"We believe for good reason that some effort was made to communicate that down to the rank and file - and it didn't happen.
"The fighters outran the capabilities of their commanders and I think that the fact that the Talibs were surprised is demonstrated in their reaction after the fall of the government.
"It took them a long time - weeks - to figure out what to do next, how to organise themselves - and they still have not really organised themselves very effectively to lead the government."
Nor do the Taliban have much support from the public, Mr Wilson said.
"They came to power not because a large share of the Afghan population wanted them to come to power but because they fought harder, longer and in a more determined manner than anybody else was prepared to do.
"The flipside of that is they don't have much in the way of popular support to fall back on as they and as the country is reeling through a whole series of problems."
Read more on Sky News:
The Taliban had promised 'amnesty for all' - but they are responsible for most violence against civilians
Taliban says women should not make long taxi journeys without male chaperone
There may be an incipient opposition, too, Mr Wilson suggested.
"The generation that the US and our European and other allies who were in Afghanistan invested in, for better or worse - most of those people are still there.
"And I think they remain a powerful potential force of influence as the country develops and evolves over the course of the coming few years.
"Which is not say that I think the fall of the Taliban is imminent or that the westernisers, if you will, or those who we invested in are about to take over, but I still think that those millions of people are or will be a force for change."