It has been many days ago, and today I looked at this for the first time. I think at this point I can only delay the defeat for the Allies and not prevent it! I thought I really needed to retake London to have a chance of winning, but in the meantime Japan gained so much momentum that they can’t be stopped anymore. So I concede here and give you the win!
I was shocked how I wasn’t able to retake London earlier in the game as the US, even when I spent almost all money in the Atlantic. I even bought a fighter and two infantry for London on the first turn so still quite some reinforcements for UK imo. Before this game, I only really played against myself so I never really faced Sea Lion. I was actually even happy to see you doing it because I thought on the long-term it doesn’t really work with the Soviets becoming so strong, and I also thought I would handle the Allies well in this situation but you proved me wrong! I think using the bid for some UK submarines might help, or even simply more reinforcements for London on UK1.
Apart from all that, this game saw some crazy tactics at various points during the game which is just awesome!
I would love to play you again, however I think that is better done some time later because right now I am pretty busy and just like right now, I will likely play extremely slowly. But maybe in the future! :)