All Against All is the story of the season our world changed from postwar to prewar again. It is a book about the power of bad ideas - exploring why, during a single winter, between November 1932 and April 1933, so much went so wrong. Historian Paul Jankowski reveals that it was collective mentalities and popular beliefs that drove this crucial period that sent nations on the path to war, as much as any rational calculus called “national interest.” Over these six months, collective delusions filled the air. Whether in liberal or authoritarian regimes, mass participation and the crowd mentality ascended. Hitler came to power; Japan invaded Jehol and left the League of Nations; Mussolini looked towards Africa; Roosevelt was elected; France changed governments three times; and the victors of 1918 fell out acrimoniously over war debts, arms, currency, tariffs, and Germany.   All Against All reconstructs a series of seemingly disparate happenings whose connections can only be appraised in retrospect. As he weaves together the stories of the influences that conspired to lead the world to war, Jankowski offers a cautionary tale relevant for western democracies today.   “[One of] the most stimulating histories of the interwar period to have been published in recent years.” - Financial Times “Engaging and thoroughly researched.” - Irish Times