I’d say get bombers and put em in Alaska with the American fleet there. If Japan wants to make subs, great, just send in the bombers, clear the zone, and protect your 4 transports. (Like you need more then 4? That’s 8 infantry a round into Asia, plenty to protect against Japan.)
What does Japan do? They either keep their flagships at home to protect the subs, or they build destroyers to protect their subs. Either way, you are now tieing up massive amounts of cash from Japan which spares Russia a little.
Option 2 is to move into their Islands. Now he has to come attack you and give you the defensive advantage. (And remember, 100% of fighters not on ACs are out of range of your fleet probably. He’s going to have to stage them then you move your fleet and he has to restage them.) All you need is Philippines and Borneo, that’s 7 IPCs and, with an IC on Borneo, you can successfully build defensive forces right there. 1 DD, 3 SS = 36 IPC. And gives you a decent offensive and defensive punch. Or you could go 1 AC, 1 SS, 2 FIG for 44 IPC, an easily attainable number for America.
Japan’s options? Attack, or do without. Meanwhile, America’s building a fleet/invasion force to hit the mainland in striking distance and in close enough proximity to not need doubled down transports (transports at start and end points.)
Hmm, come to think of it, I’d like to play a game like that. See what happens, you know? Of course, I couldn’t tell my opponent that I’m planning it. :) Gotta have J1 stay “normal”