War is hell, but it is also, always, a roll of the dice.

Donitz claimed that had he started out with 600 U-boats instead of the few he did he would have ruled the Atlantic and eliminated all US aid to England. He has a point. The Battle of the Atlantic was a close fought thing. Germany was hampered by the small number of U-boats they could muster. If a fraction of the cost of the surface fleet had been used to build U-boats, U-boats were cheap, it might have gone the other way.

Many historians note that Germans started winning the Battle of Britain when they gave up on the cities and concentrated on RAF airfields and RADAR. they only shifted back to the cities after Berlin was bombed and Hitler ordered it. This allowed the RAF to recover and trapped German fliers in a game of attrition trading airframes and flight crews for city blocks. A trade the Brits could afford to play for they had more city than the Germans airplanes.

I pointed out that had the Germans starter operations against Russia a week earlier there is good reason to think they would have captured Stalingrad and Moscow.

But things get complicated. The military allocations and possibilities multiply. But so do the diplomatic and industrial concerns.

The South Africans fought with the allies, but DeBeers allowed the German war machine to operate by selling them industrial diamonds. The allies asked them not to but didn't want o alienate their own suppliers. Throughout the war DeBeers, as perfect disinterested capitalists, sold to anyone with money. You were expected to arrange your own transport.

Very difficult to have a war machine without diamonds to machine the steel with. Most of the diamonds they needed were flown into Switzerland. Switzerland acting as diplomatic neutral ground, banker and back door to vital strategic materials was more valuable than as conquered territory. South African loyalties were split between Britain and Germany. There is some reason to believe that if England fell DeBeers would cut Germany off.

It also has to be noted that occupied England wouldn't deny the US of all suitable staging areas. Ireland, which remained nominally neutral, would do as a staging area in a pinch.

It has been pointed out that Hitler tended to make emotion based decisions that worked against Germany in the war. Presented with a fully functional jet fighter in 1942 he refused to finance the program because it was 'only useful in defense'. Two years later, after the Allied bombers had done a lot of damage he approved production of the Me-262. When they became operational in 1944 they cut through allied formations but it was too late. There were just too few with too little fuel to turn the tide.

War is like that. Personalities and emotions can work against you in subtle ways. You can win every battle and be defeated by bad timing and weather. Small amounts of materials like cobalt and industrial diamonds are vital. Cut off the supply and the war machine grinds to a halt. But it is all up in the air. I suspect that the best anyone can do is hang on and, as the man said, "embrace the horror".