This book offers a genuinely comparative analysis of the dictatorships that launched the Second World War: their origins, nature, dynamics, and common ruin. It seeks to understand their similarities and differences historically, without recourse to failed generic concepts such as 'Fascism.' The result is an unconventional and compelling analytical overview from territorial unification in the 1860s to national catastrophe in 1943/45 that places Fascism and Nazism firmly in the tradition of revolutionary mass politics inaugurated in the French revolution. Set within that overview are three chapters that interpret and explain Mussolini's poorly understood foreign policy and the character and performance of the military instruments upon which Fascist and Nazi success chiefly depended - the Italian and German armies. The chapter on the German army and the conclusion - which dissects the causes of the notable disparities between the two dictatorships in expansionist appetite, fighting power, and staying power - argue that a unique synthesis of Prusso-German military tradition and Nazi revolution prompted Germany's fight to the last cartridge in 1944–45.