Interesting comments and I have made an unwarranted assumption :oops: : that if USA has taken Japan (with resources diverted from European theater to do this), and Japan has taken over most of Russia then Russia cannot be far from falling. Obviously this is not necessarily the case depending on how the the game has been played.
Still I believe that if USSR has fallen, and with Germany holding W. Europe (6 ipc), S. Europe (6 ipc), Germany (8 ipc) along with Moscow (8 ipc) E. Europe (3), Ukraine (3) and Caucasia (spelling?) (3) then Germany could have an industrial production of 37 ipc so I would not immediately concede defeat.
I suppose my strategy would change in that the capture of Moscow would become much more urgent (thinking economic victory with whats left of Japan).
If USSR has not fallen, or cannot be made to fall within 1 turn at this point, along with some IPCs gained elsewhere (by Japan? Karelia?) then yes it almost certainly would be over for the Axis as the US then can concentrate on Germany, and/or take over Asia from Japan increasing its ipcs even more.