The Japanese advance through Russia is annoying, but it very much opens the door to shut Japan down and stall the Japanese advance.
You’ve got two options. The first of which is to sink the Japanese fleet and take control of SZ6 to prevent Japan from ferrying over units to the mainland while convoying Japan’s eventual income to zero and stopping the flood into Russia. You can trade your ships for Japanese ships early, sacrificing carriers by absorbing two hits to allow your aircraft to continue to sink ships in SZ6 (which of course means their demise too). Once the fleet is crippled, Japan is going to be stuck putting out a DD or CR at best each round in SZ6 - easily sunk by US DD/SS. By Japan ignoring income and making a bee line to Moscow, its most likely going to lose the fight in China as I’d expect India to DOW and stack up the Burma Road to get Chinese artillery out, nullifying the Japanese advantage over China. Losing Chinese income, the DEI income and getting convoyed, Japan’s going to be making less than 10 IPC/round once the US DOW occurs.
The other option is to ignore Japan and just build the US to land on Gib on Round 4 and then onto Norway/Italy/the French Minors on Round 5. A reinforcement of British units- a combination of infantry and aircraft can help prevent a German counter for the US landing. The only hope is that you put enough of a threat on Germany that it has to reverse its economic spending getting units into the fight for Moscow so that Berlin has to be defended instead of a factory of Mech supporting what I’d expect to be Armor purchases that were made earlier. India can also then ignore China and start churning out Armor/Mech and start marching toward Egypt/Afghan/Southern Russia. Japan will not be able to hold territories near Moscow for long with India spending from India1 forward on a march in that direction. Particularly as India claims all the DEI to pump its income into the 30’s. I’d let Anzac just build SS every round and continue to convoy/harass Japanese territories to further compound Japan’s problem of spending to get units towards Moscow whilst being harassed via convoy everywhere.
Basically the Japanese making the Moscow Rush equates to a boring Pacific Theater and UK, India, US all converging on Europe. Italy can easily be convoyed out of the game with a combination of SS purchases out of S.Africa, India and UK. Japan has an 8 roundish march to Moscow (unless theres a suicide aircraft punch). Germany is 7ish rounds out itself. If rounds 5, 6 and 7 equate to Allied landings in Europe, Germany has a tough decision to face with a convoy’ed Italy, an over-extended Japan and a split economy defending Europe and advancing on Moscow.
Realize you still may lose Moscow, but with the Allies entrenched in Europe with a full economic investment, India may be able to reclaim Moscow for the Russians as Germany has to reverse course instead of swinging south towards Egypt for the win.