The United States' ignominious exit from Afghanistan in 2021 topped two decades of failure and devastation wrought by the war on terror. A long-running "fight against migration" has stoked chaos and rights abuses while pushing migrants onto more dangerous routes. For its part, the war on drugs has failed to dampen narcotics demand while fueling atrocities from Mexico to the Philippines. Why do such "failing" policies persist for so long? And why do...