That’s what happened in Iraq after the withdrawal of U.S. forces in 2011. They were back five years later, dealing with the slaughterhouse that was the Islamic State. And if Biden was right about Afghanistan 10 years ago, he was dead wrong about getting out of Iraq, which he also strongly advocated. That’s the awful danger of this decision. Sometimes cutting the knot and removing U.S. troops opens the way for peace; more often, in recent years, it has been a prelude to greater bloodshed. The downside is easy to imagine: a spiral of violence in which provincial capitals fall, one by one, leading to a deadly battle for Kabul — a fight in which the people who believed most in the United States’ intervention will be at greatest risk, and pleading for help. Closing our eyes and ears to that catastrophic situation — turning away from the desperate appeals, especially from the women of Afghanistan, who fear new oppression — will require cold hearts and strong stomachs. Biden decided this week that Afghanistan’s fate, in the end, will be determined by its people.