Okay so frankly I’m less interested in how this happens, say it’s a perfect storm for communism with a more decisive Russian Civil War and German Revolution after a less harsh and sooner Brest-Litovsk (Trotsky doesn’t delay?) and therefore longer WWI. I’m more interested in what happens after.
So a Red Army-backed German Revolution gets at least to the Rhine before losing steam and finding French forces.
Lenin, who’d still be around for a few more years, wanted a USSR across Europe, Stalin was willing to concede a bit more to nationalism though.
My question, basically, is what would need to happen to have Germany in the USSR as a sort of German SFSR? What rights would need to be allowed and what events need to take place?