Two decades of post-9/11 warfare are ending with the United States effectively handing back Afghanistan to the same fundamentalist power, the Taliban, that was in control when it started. The war in Iraq, fought on false pretenses, not only distracted from the Afghanistan War but turned into a costly, morale-sapping disaster. A US-led bid to prevent genocide in Libya left anarchy behind. The campaign to crush ISIS in Syria saw the US ultimately deserting America’s Kurdish allies. And ex-President Donald Trump’s whole term alienated America’s friends and offered legitimacy to its autocratic foes. No one is now sure which path Washington will pursue in the world more than four years in advance.