If you pull off Sealion and the US isn’t in the war already or sitting on Gibraltar, they are at least 2 moves away from getting any kind of help to London. Italy should take Gibraltar if they can and block out the Mediterranean. Italy can move troops to the west coast and get into Syria and hopefully Iraq (if Russia hasn’t gotten their first) Then take over Africa. Build London up by 6-10 ipc’s per turn (now there are 6 of any kind of build you made, plus all your air units). US at that point needs to make a hard decision, liberate Europe or kill Japan. Fact is they cant do both. Germany and Japan are making a combined 120-140 ipc’s at that point and Italy can make an easy 30+ with their NO’s running wild in Africa. $ wise, game over, and you didn’t even have to make a move on the US. Still a lot of factors have to be taken care of, like is there still an allied NAVY in the Mediterranean? Does Italy still have any NAVY left? What kind of landing force is left in London. And where is Russia? Can Japan put pressure on Russia? Is Japan bombing the heck out of Calcutta?
Germany cannot go “hog wild” with a competent UK/Soviet player without some truly decent dice luck. Germany can push up to Moscow, but they often times can’t take Moscow immediately. That, and they can’t really spend their resources in any way but to facilitate as much power as is possible against Russia, or risk losing a turn (or worse, two), toward the eventual goal in the east.
Right about the time the European Axis are crashing the gates or ducking south for that sweet, sweet Caucasus/Volgo/Middle East money, America should be turning around or have already turned around form the Pacific.
On the other hand, Japan fucking can go hog wild without American intervention: J1 DoW specifically. I favor 100% Pac buys as the US (apart from maybe the first 52 or a sub or two a turn or whatever else, depending on a ton of situations that can’t be covered here) because the sooner you can start crumpling up Japan, the sooner you can go try to play hero in Europe.
It might be worth mentioning that Hawaii and Gibraltar are “only” two turns away from one another. It is not impossible to change your mind. It’s usually not the best idea, mind you, but it is an option, and it is occasionally useful.