The Vatican's dealings with the Weimar Republic and the Third Reich have long been swathed in myth and speculation. After almost seventy years, the crucial records for the years leading up to 1939 were finally opened to the public, revealing the bitter conflicts that raged behind the walls of the Holy See. Anti-Semites and philo-Semites, adroit diplomats and dogmatic fundamentalists, influential bishops and powerful cardinals argued passionately over the best way to contend with the intellectual and political currents of the modern age: liberalism, communism, fascism, and National...