Responding to the disastrous fallout of his Afghanistan withdrawal, President Joe Biden declared that the “buck stops with me” — and then spent the rest of his first public address on the crisis shifting blame and proffering the same flawed arguments that led us to this tragic point. We must scrutinize those arguments if we are to learn the lessons of these failures and avoid them in the future. Indeed, Biden’s obviously incorrect statement that the Afghanistan withdrawal could not have been handled better suggests we have a lot of work to do. To be sure, the U.S. government’s most important task at this point is completing the urgent evacuation of thousands of Americans stranded in Afghanistan by the incompetent implementation of the administration’s poor decisions. Any remaining time should be used to evacuate Afghans...