There’s plenty of blame to go around for the 20-year debacle in Afghanistan—enough to fill a library of books. Perhaps the effort to rebuild the country was doomed from the start. But our abandonment of the Afghans who helped us, counted on us, staked their lives on us, is a final, gratuitous shame that we could have avoided. The Biden administration failed to heed the warnings on Afghanistan, failed to act with urgency—and its failure has left tens of thousands of Afghans to a terrible fate. This betrayal will live in infamy. The burden of shame falls on President Joe Biden.