Twenty people involved in the November 2015 terrorist attacks in France – the largest terrorist event in France — in which 130 were killed and 490 wounded, went on trial in Paris Wednesday – six of them in absentia.

Top law enforcement officials have described violent extremism — especially racially or ethnically motivated extremism— as the greatest domestic threat facing the United States. The Biden administration has requested tens of millions of dollars to fight it. Yet the research on what an effective strategy might look like has too often failed to engage the people who might know best: those who have lived that life and left it behind.

More than 91,000 responders were exposed to a range of hazards during recovery and clean-up operations, with 80,785 enrolling in the World Trade Center Health Program (WTCHP) set up after the attacks. 3,439 are now dead – far more than the 412 who died on the day of the attacks – and many of those alive have been suffering from a series of ailments related to the work at the Twin Towers site.

The Taliban managed to seize power so quickly because it used Afghanistan’s human geography to exploit that state’s fragility: The country’s low population density empowers fast-moving and cohesive attackers, for which the poorly trained, disorganized, corrupt, and unmotivated Afghani army was no match. Alec Worsnop writes that, still, the evacuation could have been made safer and more orderly if a small Western contingent with air support would have been left behind to hold the Taliban at bay for a few more weeks — but this would only have delayed the inevitable: “Leaving a limited outside force in place, without significant reinforcement, could not have prevented an inevitable Taliban takeover within a matter of months,” he writes. “There were few prospects for long-term stability without a notably larger foreign troop presence.”

William Dalrymple, a Scottish historian and author of Return of a King: the Battle for Afghanistan 1839-42, writes that the West’s 20-year failed effort in Afghanistan was as inevitable as it was predictable for anyone with “a grasp of history”: In Afghanistan, there had been only the briefest of “moments of anything approaching a unified political system. Afghanistan has always been less a state than a kaleidoscope of competing tribal principalities governed through maliks or vakils, in each of which allegiance was entirely personal, to be negotiated and won over rather than taken for granted.”

It used to be said the Afghanistan is the “graveyard of empires.” Sumantra Maitra writes that the U.S. failed 20-year war in Afghanistan will go down as one of the more consequential wars –a “paradigm-shifting event” — because Afghanistan proved to be the graveyard of ideologies as well: “Evangelical Marxism failed in Afghanistan, as did evangelical liberalism.”

It appears that the Taliban regime intends to completely revamp the structure of government when it formally embarks upon its administration from 1 September — for example, the Taliban plans to get rid of the position of the elected president, and, more importantly, it aims not to elevate or project a single individual to the position of supreme leader. One thing is not going to change: The individuals who are going to run the main government departments and security services are all hard-liners.

“The primary interest for China in Afghanistan is ensuring stability so that no unrest would spill over into the wider region and China in particular. In this sense, the U.S. presence in Afghanistan has been a positive for China as it has played the security role at no cost to China. Now, China will have to develop its own relationships with the Taliban,” says Harvard’s China expert Tony Saich.

Twenty years ago, Islamist terrorists, trained under the Taliban regime in Afghanistan, attacked the United States, killing nearly 3,000. The Biden administration is withdrawing all American forces from Afghanistan, and the country will again be ruled by the Taliban. This withdrawal was unnecessary.