During the first half of the twentieth century Europe suffered a cataclysmic change. The lives of millions were destroyed, millions more lives blighted. What led to such a chain of catastrophes? The fratricidal Great War marks the turning point in the history of Europe. There is no single cause that explains it all, but a multiplicity that need to be untangled. Paradoxically industrial progress also promised better living for Europe’s people, the very industrial progress that increased manifold the impact of war. At the heart of Europe’s conflict was the mutual fear of the ‘hereditary foes’, France and Germany. Around this core, other countries lined up on one side or the other, every local regional conflict that might have been settled as before by limited war, threatened to engulf the whole of Europe, until it finally did so. Europe would not come to rest as long as national leaders believed in a Darwinian world of conflict where the strong must either grow stronger or succumb. Ultimately, the conviction grew that there could only be one superpower in the world. The process of reaching that end seemed inevitable. Mass armies, guns, battleships were the means to that end. It was only a matter of time. Statesmanship was about judging when the time was ripe to strike. Meantime, while Europe was moving toward Armageddon, political and social change accelerated. It was not inevitable that the people would follow their national leaders. Tragically they did, under patriotic flags. The weak band of international Marxists early in the century denounced the imperialist leaders, but they too did not preach peace. They wished to replace wars between nations with civil wars within. The voices of peace and reason condemning a European fratricidal conflict were drowned.