Adolf Hitler is probably the last of the great adventurer-conquerors in the tradition of Alexander, Caesar and Napoleon, and the Third Reich the last of the empires which set out on the path taken earlier by France, Rome and Macedonia. The curtain was rung down on that phase of history, at least, by the sudden invention of the hydrogen bomb, of the ballistic missile and of rockets that can be aimed to hit the moon. In our new age of terrifying, lethal gadgets, which supplanted so swiftly the old one, the first great aggressive war, if it should come, will be launched by suicidal little madmen pressing an electronic button. Such a war will not last long and none will ever follow it. There will be no conquerors and no conquests, but only the charred bones of the dead on an uninhabited planet.