I'm kinda getting bored with this discussion, so I think we'll have to cut it or change topic soon
.
But anyway...
The Americans didn't really harness their resources effectively... certainly not as effectively as the Japanese... but rather they simply threw everything they had at their enemies until the latter died under the weight of all those resources. But you're quite right - as long as America wasn't getting bombed (which would be quite impossible for the Japanese to achieve), there was no hope. Sooner or later, an American offensive would have reached the Marianas, and the firebombing would have started (actually, I wonder if anybody has ever considered putting the commanders responsible for
that idea on trial for crimes against humanity). Not to mention, eventually the nuke would have come along.
The height of the U-Boat menace only passed because the Americans finally got off their asses and started building escort vessels (before this time, escort vessels were at the very end of the things-to-do list). But what if the shipyards were too busy churning out new carriers and destroyers for the Pacific front instead? You're right in that neither the UK nor the Russians would have been knocked out of the war, but the war would have lasted a year or two longer (which, imho, would in itself have been almost as disasterous as an Allied defeat).
I'm also not entirely sure what Hitler thought he was doing in Russia. Maybe he was skipping class the day they taught about Napoleon?
Seriously, he had a chance, but he was pretty much an absolute idiot. Why bother opening up a second front, when he could have smashed the British out of the Middle East? Why declare war on the Americans? Why waste money building stadiums in preparation for victory celebrations, while his forces were freezing to death in Russia?
Now, lastly, about Roosevelt. Yes, the Japanese gave him support for war - war against the Japanese. You have to consider that this was not synonymous with war against the Germans. But come to think of it, it dinna matter - Hitler was dumb enough to declare war out of sympathy for the Japanese. He basically untied Roosevelt and gave him a gun.