national socialist Germany's only chance of success would be to avoid Operation Barbarossa or engage only Russia and not the west. The number of casualties on the eastern front compared to the western was on a 10:1 scale. For every 10 soldiers who died in the east, 1 died in the west.
Fighting Russia could have been their best bet, putting most of their troops on only one front and stacking their power on those fronts. Casualties would have still be high, but Russia would have ultimately lost. They'd be cutting their worst enemy down much quicker, and more effectively.
The German Reich would most likely allocate their forces, rebuild, and advance them, continuing work on different scientific marvels, such as the atom bomb. If this were the case, then they'd also use these new weapons and their newly strengthened forces to blitzkrieg the West. France would still be in no position to resist, and would fall just as they did in our timeline. Britain would still be difficult to overcome considering the dedication of the RAF, but if we still consider the advancements in technology, then they would still lose after a hard fought battle. It could even be that major military outposts or even major cities could be decimated by a possible atomic bomb, completely crushing the western morale and their strength.
If Germany was to only fight Russia during this time period, and Japan still attacked the United States, a Japanese-American war would still unfold (without the United States declaring war on national socialist Germany), with Japan ultimately losing, but at the same time costing the United States. Given the fact that Germany at this time has possibly developed the nuclear bomb, this means that the United States did not, and therefore could not have ended their war with Japan with atomic weaponry. This would then require a full-scale land invasion of Japan also called Operation Downfall. This operation would leave the United States with massive amounts of casualties and debts, morale would drop and the American public would not view the war as highly as they did. There would be efforts to avoid war with any other major power at the time, this includes national socialist Germany. There's a lot of political mumbo-jumbo, where we might hold a military presence over Japan and some other large pacific land masses, like the Philippines and the entirety of Korea. This could prove either beneficial or cause a negative impact on the United States. (I say the entirety of Korea, as because of the fall of Russia, communism would not prove very beneficial to poor nations, so it's spread decreased significantly, possibly even keeping Chinese communism from rising.)
Germany would rule over this:
and maintain puppet governments in both France, UK, and Italy. Switzerland, Netherlands, Belgium, Denmark, and Norway would definitely be apart of the German Reich however, despite what the map displays. It's hard to say what would exactly happen to the Balkans, and then to the Arab region, or even Sweden, under these circumstances.
Africa would most likely be stomping grounds for Germany and Italy during this time. Germany reclaiming lost colonial territories from the 'War to End all Wars' and claim untapped resources that can prove useful.
Honestly, moving away from a lot of science fiction and alternate history, we would not all be speaking German. I do believe that it would result in a cold war regardless, with it being the German Reich versus the United States and it's allies. Given that communism is no longer appealing, China's nationalist party would remain in power, and would have considerably more territory and a larger sphere of influence than it does today. They would prove a great ally in times to come, with inexorable proxy wars likely to occur, mostly in Africa and the Middle East. Certain modern issues would still occur, such as Pakistan/India conflicts. All major powers would, eventually, obtain nuclear arsenals, so the German Reich, China, India, United States. Very few smaller states would also carry nuclear arsenals, like Pakistan.
A United Nations-esque program would eventually be instated, but it would take many years and would not be as effective as our United Nations are today. Somewhat reminiscent of League of Nations.
This just what I think they'd have to do to win and then what they'd do afterwards, and some aftermath effects.
