[*Buzzsaw*]

Salute

WWII, like WWI, was a war determined by simple raw manufacturing power.

What won the war was the fact the combined economic power of the Allied countries was much larger than the combined economic power of Hitler's Germany and all its conquests, plus Italy as well as Japan and all its conquests.

Plus the fact the largest of the Axis economies, Germany, was mismanaged from 1939 to 1942 and produced much less than it could have. Part of this was Hitler's doing, he was afraid of another revolution in Germany along the lines of the 1918 one if he cut back on luxuries and instituted rationing and a 24 hr a day war economy. So Germany remained on a peacetime manufacturing schedule for the first 3 years of the war, with German citizens enjoying most of the perks of peacetime.

And of course, slave labourers and the workers of defeated countries won't give you the same production levels as committed citizens. So for example, even though France produced a lot of weapons and resources for Germany, and even though its millions of captured soldiers provided much useful slave labour in German factories, the amount of production was far less than the French economy would have produced had it been for its own armies and people, and much of the products provided were either of poor quality or deliberately sabotaged.

On a more relativistic level, you can also say Hitler and the Japanese militarist's philosophy and moral code alienated the great majority of the world and stiffened their resolve. When you declare the rest of humanity are inferior and worthy only of death and extermination, it tends to provide incentive to resist.