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 who worked with the U.S. government and who are confronting Taliban retribution. Once those vital tasks are complete, we must resist the temptation to move on without self-reflection. There are many reasons for the catastrophe we are witnessing in Afghanistan, and we should seek to understand all of them. That effort should start with Biden’s decision to withdraw from Afghanistan based on self-delusions regarding the nature of our enemies there and the need for a continued military presence. To be clear, the failure has been a bipartisan one. President Donald Trump embraced many of the same misconceptions, including the all-too-prevalent...