In that regard, the United States joins a line of notable predecessors, including Great Britain, in the nineteenth century, and the Soviet Union, in the twentieth. Those historic precedents don’t make the American experience any more palatable. In Afghanistan—and, for that matter, in Iraq, as well—the Americans did not merely not learn from the mistakes of others; they did not learn from their own mistakes, committed a generation earlier, in Vietnam.

The main errors were, first, to underestimate the adversaries and to presume that American technological superiority necessarily translated into mastery of the battlefield, and, second, to be culturally disdainful, rarely learning the languages or the customs of the local people. By the end of the first American decade in Afghanistan, it seemed evident that the Western counterinsurgency enterprise was doomed to fail, and not only because of the return of the Taliban in many rural parts of the country: the Americans and their nato allies closed themselves off from Afghans in large regional bases, from which they operated in smaller units out of combat outposts, and distrust reined between them and their putative Afghan comrades. “Green-on-blue attacks,” in which Afghan security forces opened fire on their American and European counterparts, became alarmingly frequent. The Taliban, meanwhile, grew inexorably stronger…

Most of the Afghan men whom I met and who led battles against the Taliban two decades ago are now dead. Almost all were killed, in separate assassinations, as part of the Taliban’s plan to return to action. Their comeback has taken twenty years, but it is a classic example of a successful guerrilla war of attrition, and has involved all the usual elements of guerrilla strategy: a stealth campaign of hit-and-run military attacks, selective assassinations to demoralize their adversaries, and acts of terror that both weakened the government and created an atmosphere of abject compliance from local populations. A public campaign of hearts and minds followed, accompanied by decoy negotiations with the government and its allies in order to promote the idea that, as a force, the Taliban are not really extremist and are, in fact, open to dialogue, even to internal change. But the Taliban, by their very nature, are fundamentalists, believers in a strict Quranic credo.