The First [World] War explains the second and, in fact, caused it, in so far as. one event causes another,' wrote A. J. P. Taylor in his Origins of the Second World War. "The link between the two wars went deeper. Germany fought specifically in the Second War to reverse the verdict of the first and to destroy the settlement that followed it." Not even those who most vehemently oppose Mr Taylor's version of inter- war history will take great issue with those judgements. The Second World War, in its origin, nature and course, is inexplicable except by reference to the First; and Germany - which, whether or not it is to be blamed for the outbreak, certainly struck the first blow-undoubtedly went to war in 1939 to recover the place in the world it had lost by its defeat in 1918. However, to connect the Second World War with the First is not, if the former is accepted as the cause of the latter, to explain either of them. Their common roots must be sought in the years preceding 1914, and that search has harnessed the energies of scholars for much of this century. Whether they looked for causes in immediate or less proximate events, their conclusions have had little in common. Historians of the winning side have on the whole chosen to blame Germany, in particular Germany's ambition for world power, for the outbreak of 1914 and hence to blame Germany again-whatever failing attaches to the appeasing powers for that of 1939. Until the appearance of Fritz Fischer's heretical revision of the national version in 1967, German historians generally sought to rebut the imputation of 'war guilt' by distributing it elsewhere. Marxist historians, of whatever nationality, have overflown the debate, depicting the First World War as a 'crisis of capitalism' in its imperialist form, by which the European working classes were sacrificed on the altar of competition between decaying capitalist systems; they are consistent in ascribing the outbreak of the Second World War to the Western democracies' preference for gambling on Hitler's reluctance to cross the brink rather than accept Soviet help to ensure that he did not. These views are irreconcilable. At best they exemplify the judgement that 'history is the projection of ideology into the past'. There can indeed be no common explanation of why the world twice bound itself to the wheel of mass war-making as long as historians disagree about the logic and morality of politics and whether the first is the same as the second.