To be fair, if you look at Russian demographics, subtract out all the childbearing age people who have either exited en-masse in those two waves - or been mobilized to die - they're pretty done with invading.

That said, Ukraine has similar demographics. Settler societies (e.g. US, CAN, AUS) have solved this with immigration. I'm hoping the rebuilding of Ukraine turns it into a beacon for immigrants (and there are a number of Russian speakers who no longer want to live in Russia...). If you read ‘American Nations’, it shows that immigrants pick up folkways from their new homes, so they’re not a lost cause.

It would be perfect if Ukraine turned Russia's collapse into something great. BTW/FWIW, I've started on a reread of Taras Bulba. The Ukrainian drive for self-determination goes way, way back. Yes, he was fighting the Polish empire, but fighting none the less...