A specter is haunting Europe. Not Vladimir Putin’s Russia, whose imperial ghost has returned in the invasion of Ukraine. Not illegal immigration, which could be called a tide, except it runs in only one direction. Not Islamic extremism, which Europe’s political class still largely insists is a figment of the “far Right” imagination. Not even the Apocalypse of St. Greta of Thunberg, the climate climacteric at the end of the world. The specter haunting the minds of Europe’s leaders does not come from the south or the steppes, as the Umayyad Caliphate and Genghis Khan did. It comes from the west, from Europe’s modern conqueror: the United States of America.