Well, let's assume America, England, Japan and Italy did not get into the mix. Therefore it becomes Germany vs Russia.
I'm pretty sure that Russia would win.
Are we just throwing their armies at each other or imagining there is a war?
Because Russia could just throw lots and lots of men at Germany.
And then there is the question of where would this RussiaVGermany take place?
Does Germany invade Russia again, or does Germany get attacked?
And if Germany isn't being attacked on the other side by the Allies, then it has it's full strength against Russia.
I don't know. I'd say it could sort of go either way.
Whatever the outcome, it would be grissly
Also, if all countries were, lets say, for themselves and didn't defend each other, then Germany would steam-roll over much of Europe. Logically, if they weren't having England attack to defend France and others, then they wouldn't even bother with the UK.
And if Germany were taking it smooth and just knocking country after country, they'd get even bigger eventually. If Germany had the time and was't plagued by other countries trying to stop it, it could take it slow and become greatly powerful.
But that's all hypothetical.