It turns out that a lot of former senior officials were opposed all along to the US-led Nato mission in Afghanistan in 2001.
Take Jonathan Evans, who was head of Britain’s MI5 internal security service from 2005 to 2013. He declared on Friday that he had preferred a different type of response following the intervention to depose the Taliban.
“We should have focused very narrowly on counter-terrorism objectives in regard to Afghanistan,” he said. “It was very worthy, but rather ambitious to think that we could reshape the whole country.”
Professor Michael Clarke, former head of the Rusi think tank, wrote last week of the availability of the “dagger through the brown envelope” option.
“[This was] to leave a metaphorical note on the table before leaving which said, ‘don’t let international terrorists operate from your country again, or we’ll be back’.”
Instead Mr Clarke says the UK made a strategic decision from the moment of the 9/11 attacks to commit alongside the US to rebuilding Afghanistan to a western-determined model as well as the global war on terror.
The restoration of Taliban rule has dealt a severe blow to nation-building as an international policy. It has upended the credibility of western counter-terrorism strategies. Less noticed, an unfolding crisis is also engulfing counter-extremism.
Interviewed after the Taliban takeover, Ben Wallace, the British defence secretary, shared his concerns at the emergence of a “world order” in which western resolve was perceived as weak. In particular, he warned the most potent terrorist threats would grow.
“Around the world Islamists will see what they view as a victory,” he predicted.
US President Joe Biden’s decision to withdraw all operations in Afghanistan was not just about bringing to an end the “forever wars”. It also opened up the most basic questions about the strategies pursued over the past two decades.
The US took a security-dominated approach to counter-terrorism, most obviously though the Global War on Terror. This combined not only warfare but also development policies and foreign policy objectives, like advancing democracy.
Other countries have had a more blended approach. The UK went to the battlefield with America, not only in Afghanistan but also Iraq and elsewhere. Yet it also more fully developed policies addressing radicalisation and the spread of harmful ideologies.
These counter-extremism initiatives were very bound into the fight against Al Qaeda as they were developed and for that reason are vulnerable now to a backlash inspired by the events in Afghanistan.
There has been a constant negativity around counter-extremism, in particular that it was overly focused on the threats that were triggered by Al Qaeda. The Soviet-coined term “whataboutery” often applies – analogous arguments are raised to undermine and debilitate the arguments of opponents.
A review of the UK’s flagship counter-extremism programme, Prevent, is taking place in this context. It is buffeted by a cultivated distrust. One argument goes that it does not adequately address non-Islamist terrorism (“What about the far right?”). There are demands for greater emphasis on “white rage” or other forms of hatred on social media.
As Mr Wallace indicated, the Taliban victory does give Islamists an uplift. After 20 years of condemnation of its threat to life and liberty, the Taliban has not only survived but won.
So many people will resist anew when confronted with counter-extremism messages. They will be encouraged by mainstream politicians who are opposed to Western policies.
When the British Parliament was recalled last week, there was significant social media traffic for MP Zarah Sultana. She made the case that the Afghanistan intervention was not launched in response to an attack. It was imperialism.
According to Ms Sultana, the campaign was illegitimate because it was built on lies.
Policing social media platforms has recently hogged more headlines than counter-extremism in the West. It is an irony then that social media companies are conflicted about Taliban accounts and how deal with its messaging, now that it runs a country.
Technological changes have been so rapid and so far-reaching that counter-extremism policies are in desperate need of rethinking. Social media campaigns are needed that show that these platforms can been a good friend but a bad master. Reminding parents, for example, that their child is vulnerable to radicalisation is a necessity.
Those who seek to exploit social, economic, ideological and political differences are growing in number and sophistication. Addressing those grievances with development policies is now more important than ever.
Counter-terrorism clearly faces new challenges. Security services like those once run by Mr Evans must be scrambling to first ensure new threats are tackled, but also that their strategies quickly adapt to the Taliban’s rise.
The ideological battles within counter-extremism must now be refought. Recognition that the intellectual energy unleashed against Al Qaeda after 2001 has dissipated and run up against newly invigorated opponents is just the first step.
The US itself should consider embarking on its own quest for a domestic counter-extremism framework that has broad public support. Policies in the UK, France and elsewhere in Europe need to demonstrate effectiveness, fairness and a sharper focus on ideological threats.