Winner of the 2010 George Louis Beer Prize of the American Historical Association.The struggle between Hungary and Romania for control of Transylvania seems at first sight a side-show in the story of the Nazi New Order and the Second World War. These allies of the Third Reich spent much of the war arguing bitterly over Transylvania's future, and Germany and Italy were drawn into their dispute to prevent it from spiraling into a regional war. But precisely as a result of this interaction, the story of the Transylvanian Question offers a new way into the history of how state leaders and national elites have interpreted what "Europe" means. Tucked into the folds of the Transylvanian Question's bizarre genealogy is a secret that no one ever tried to keep, but that has remained a secret nonetheless: small states matter. The perspective of small states puts the struggle for mastery among its Great Powers into a new perspective.