Fall of Afghanistan: Taliban takeover prompts fears of a resurgent al-Qaeda

The lightning-fast changes in Afghanistan are forcing the Biden administration to confront the prospect of a resurgent al-Qaeda, the group that attacked America on September 11, 2001, at the same time the US is trying to stanch violent extremism at home and cyberattacks from Russia and China.

With the rapid withdrawal of US forces and rise of the Taliban in Afghanistan, "I think al-Qaeda has an opportunity, and they're going to take advantage of that opportunity," says Chris Costa, who was senior director for counterterrorism in the Trump administration.

"This is a galvanising event for jihadists everywhere."

Taliban fighters patrol in Kabul, Afghanistan. Photo / AP

Al-Qaeda's ranks have been significantly diminished by 20 years of war in Afghanistan, and it's far from clear that the group has the capacity in the near future to carry out catastrophic attacks on America such as the 9/11 strikes, especially given how the US has fortified itself in the past two decades with surveillance and other protective measures.

But a June report from the UN Security Council said the group's senior leadership remains present inside Afghanistan, along with hundreds of armed operatives. It noted that the Taliban, who sheltered al-Qaeda fighters before the September 11 attacks, "remain close, based on friendship, a history of shared struggle, ideological sympathy and intermarriage".

White House national security adviser Jake Sullivan speaks during the daily briefing at the White House in Washington. Photo / AP

Pentagon spokesman John Kirby acknowledged that al-Qaeda remains a presence in Afghanistan, though quantifying it is hard because of a reduced intelligence-gathering capability in the country and "because it's not like they carry identification cards and register somewhere".

Even inside the country, al-Qaeda and the Taliban represent only two of the urgent terrorism concerns, as evidenced by unease about the potential for Islamic State attacks against Americans in Afghanistan that over the weekend forced the US military to develop new ways to get evacuees to the airport in Kabul. The Taliban and Isis have fought each other in the past, but the worry now is that Afghanistan could again be a safe harbour for multiple extremists determined to attack the US or other countries.