I wonder what's going on in the Pacific now. I think the last update we had was a pyrrhic victory at Midway, then a huge land war in India. The Japanese seem to have just been ejected from Samoa as well, but I assume they have New Guinea and the Solomons?
I think attriting their air forces will be much more difficult than OTL. It doesn't seem like there were any long attritional air battles like the OTL battles in the Solomons and Guadalcanal, while it seems that they are in a much stronger position industrially and capable of bringing in a lot of new aircraft with ~2000 hp propellor engines, so they won't be stuck with the Ki-34/Zero as their main fighter. (IIRC they do get the A7M in service by 1943 ITTL).
Then again, once the Allies finish up in Europe, if the Japanese are caught with a lot of troops in India it could be a disaster as I really don't think it would be easy to make an escape through Burma if they can't ship out through Rangoon. Both FBU and UASR seem to have much larger naval forces in the Mediterranean, and they might quickly regain the advantage when shifted over.
I wonder if the USSR/UASR would bother retaking China or focus resources on Japan. Would also be interesting to see if the USSR participates in a TTL "Downfall" as the two militaries are tied extremely closely.