Just some rambling speculation here. It seems to me that somehow World War II was actually the war that World War I was thought to be, and vice-versa. I cite the following.
In World War I, both sides believed that the war would be won by whichever side mobilized the fastest and overran the enemy’s territory. The allied propaganda screamed that Germany was lead by the evil Kaiser, and that German troops were massacring civilians in occupied Belgium. The allies claimed that civilization itself was under assault by the barbarians, and that the war was a noble crusade blessed by God himself.
After WWI was over, most in the west were bitterly disillusioned. The war had been a bloody stalemate in the trenches. The allies had fought for power rivalry, not shining ideals. The Kaiser had been no more autocratic than the Tsar of allied Russia, and stories of German atrocities were exaggerated by propaganda.
Well never again people said. Pacifism became fashionable, and patriotism was denounced as jingoistic. War was always wrong, never right. All you needed was a strongly fortified defensive line, since offensives would always be futile. As Hitler came to power in Germany, warnings of what the Nazis were planning were dismissed as the usual propaganda.
Then World War II came; the defensive lines were breached or bypassed, and the first phase of the war was won by the side that was swiftest and most mobile, Germany. Reports that the Nazis were deporting and killing millions of Jews were dismissed at first, but eventually were shown to be true. Hitler turned out to be not just a German patriot but a homicidal madman. Civilization in the form of liberal democracy was indeed under siege by the barbarians. Not only had pacifism failed, but by appeasement had actually provoked the crisis.
In summary then, it seems that if generals are always preparing to fight the last war, then it’s equally true that politicians always learn the wrong lesson from the last war.
Soon afterwards, Deimos simply vanished from the sky.