Of all the empty, pointless statements that are periodically repeated by Western politicians, none is more empty and pointless than this one: “There can be no military solution to this conflict.” That was what Ban Ki-moon, then the UN secretary-general, said back in 2013: “There is no military solution to the conflict in Syria.” John Kerry, then secretary of state, echoed those same words—“No military solution to the conflict in Syria”—on many occasions, including in 2013 and again in 2015. Zalmay Khalilzad, the U.S. special representative for Afghanistan, said this on August 3: “We believe there is no military solution” in Afghanistan. “Ultimately, for Afghanistan to have peace and stability there needs to be a negotiated political settlement.” Even British Prime Minister Boris Johnson repeated this, solemnly, in July: There is “no military path to victory for the Taliban.”

The phrase sounds nice, but it’s not true. In many conflicts, probably Syria and certainly Afghanistan, there is a military solution: The war ends because one side wins. One side has better weapons, better morale, more outside support. One side has better generals, better soldiers, more stamina. Or, sometimes, one side is more willing to use violence, cruelty, and terror, and is more prepared to die in order to inflict violence, cruelty, and terror on other people.

Peace negotiators, experts in conflict prevention, UN officials, European Union officials, and myriad American and international diplomats don’t want to believe that this is true, because it doesn’t reflect the values of the world that they inhabit. They don’t know any Taliban fighters, Hezbollah militants, or Russian mercenaries and can’t imagine what the world looks like from their point of view. But violent extremists, contrary to the popular image, can be quite rational: They can calculate exactly what they need to do to win a battle, or a war, which is precisely what the Taliban has just done in Afghanistan. There was a military solution, and the group has been waiting for a long time to achieve it. Now it will convert the violent extremism of its movement into a violent, autocratic, tyrannical state.

The need to prevent this from happening in other places—to prevent violent extremists from invading places where people would prefer to live in peace and in accordance with the rule of law—is precisely why we have armies, weapons, intelligence agencies, and spies of various kinds, despite all of the mistakes they make and the ugly things they sometimes do. The need to prevent violent extremists from creating structures like al-Qaeda or rogue, nuclear-armed regimes is precisely why North Americans and Europeans get involved in distant and difficult conflicts. That’s why the U.S. has military bases in Germany, South Korea, and Kuwait, among other places. That’s why even the Dutch were persuaded to set up a base in Afghanistan, which I visited in 2008 (and which even then seemed pretty precarious).

That’s also why the phenomenon of liberal internationalism—or “neocon internationalism” if you don’t like it—exists: Because sometimes only guns can prevent violent extremists from taking power. Yet many people in the liberal democratic world, perhaps most people, don’t want to believe this. They have long found these tools either too distasteful or too expensive. Like Ban Ki-moon and his many imitators, they sometimes even pretend that these tools are not necessary at all, because conflicts can be resolved by “talks” and “dialogue” and “cultural exchange.” They pretend that there are always peaceful solutions that have somehow not been considered, that there is always a nonviolent answer that has somehow been ignored, and that “solidarity” with the women of Afghanistan, without a physical presence to back it up, is a meaningful idea. “Hang in there sisters!” wrote the Greek economist Yanis Varoufakis, in a tweet that celebrated the fall of “liberal neocon imperialism” and unwittingly illustrated just how delusional the anti-war left has become. Hang in there, sisters? The fall of Kabul makes a mockery of that kind of language and shows up those who use it as fools.