So my group has completed a game where Japan went for America. We figure that whether or not Japan wins is dependent on a few things.
I don’t remember whether the final assualt on WUS happened on J3 or J4. I think it was J4, and they waited until J3 to attack Alaska? Either way, the statistics were about a 45% chance for Japan to take WUS. They needed some AA misses to throw it in their favor.
There really is little that the UK and ANZAC player can contribute to the defense of WUS. The best thing for them to do is go crazy in the absence of the Japanese forces. By the time America fell, the UK had liberated most of China, and had several rounds to build up a navy with the help of the DEI income. Australia also had a bonus going on, adding 2 loaded carriers to supplement defense of the UK fleet.
Japan thought about going straight for Australia, but the UK fleet with transports(deploying from Kwangtung and Kiangsu factories) was already threatening Japan.
While America had fallen, they only gained +10 income from America, +Mexico +Alaska, while giving up on their territories in the Chinese mainland. They were being out produced by the Allies, and out of position to restablish a hold on the mainland.