The USSR isn't coming back though. Putin wants nothing to do with that and you can see that in how their military is organized. The USSR had around 5 million men at arms at the height of the cold war. The Russian Federation has half that on paper, likely less due to losses in Ukraine. If the Russians are going to take all of Ukraine, the Baltic states, Poland, Romania, Bulgaria, Moldova, Slovakia, Hungary, the Czech Republic, half of Germany and all the central Asian 'stans then they will need to mobilize tens of millions of men. There are zero indications that Putin has any plans to do that. They have enough to handle Ukraine and that's about it