Arctic strategy?
It's a very interesting timeline--with the Germans much more evenly matched to the Allies. I would assume that ITTL, Germany possesses Danish Greenland? ???
This might interest Germany in developing some ships with icebreaking and Arctic warfare capabilities--something the US is now discovering that it is deficient in right now ITTL. Sith possession of Svalbard (which has mineable coal deposits), Novaya Zemela, Severnaya Zemela, New Siberian Islands Wrangel Island , Big Diomede Island and the Kommanderski Islands (the last two or three could be possessed by Japan), Germany could control the Northern Sea Route, which opens an Axis channel to the Pacific for 4 months out of the year. All of these islands can have coaling stations.
If Germany is not worried about the Monroe Doctrinshe can also occupy the Canadian Arctic Islands.(some of which Norway claimed until the 1930s). As enemy territory, they are fair game for Germany.
These , includie Baffin Island and the Hudson Bay Islands, swhere it is possible to build airfields that can strike the cities of Ohio, Michigan, Indiana and Illinois, as well as Pittsburgh. With icebreakers, all of these places can be reached in the summer. And ice roads can be built to connect them in the winter. And U-boats can travel under the ice and surface through the ice wherever they need to to replenish their air tanks if they are engineered to do so, which is not difficult. Think of how readily the Nautilus surfaced at the North Pole in 1958, just for the publicity. Nazi bases in the American Arctic would give the US fits and force the US and Canada to get serious about infrastructure and settlement in the Arctic. and Alaska.
Frankly, ITTL, until very recently, the Arctic Ocean has been a very big strategic blind spot for everyone except the Russians. But even ITTL, the Nazis and the Japanese could have used it, if for nothing else, for faster U-boat transportation between the two Axis nations than going the long way around Africa.