The concept of this book seems to start from an implicit but inescapable acknowledgment. Compared to the over-specialization, the fragmentation, the technicality, and finally the undeniable overproduction of the historiography on World War II, the history writing on World War I is remarkably advanced in producing an integrated, intellectually ambitious analysis of the experience of the war and its impact on post-1918 Europe. This historiography attained a comparative European scale, and it reached into the realms of social and cultural history. Mechanized warfare during four long years had brought violence on an unprecedented scale. Mass-mobilization, massive casualties, and an entire generation traumatized by mutilation, shell-shock, and the experience of daily horror had profoundly impregnated European societies with the experience of this war, including a home front of mourning widows and orphans, of depleted villages, factories, and neighborhoods. The experience, moreover, had been fundamentally identical for all belligerents, and it had thereby unified the European continent through a common fratricidal cataclysm. The widow and the soldier, the German and the British, had all, somehow, lived the same war. Even if these European societies chose in the two decades following the war very different paths – aggressive fascism or pacifisme municheois – victors and vanquished initially had to cope with a very similar legacy of mass death, mutilation, and war trauma.