> Or on the diplomatic table. While I agree it is a good thing to send Ukraine all we reasonably can, it is a nonzero probability Putin gets into hot water and ousted - bad health, pissed-off bureaucracy, domestic protests once he's forced to conscript people in central (ethnic) Russia.
Ukraine being a part of Russia is a mainstream opinion in Russia. It's a core part of Russian propaganda abroad and has been so since the 1800s (Novorossya).
I'm not saying it's impossible, but a new leader will adopt many of the nationalist tropes.
Russia completely leaving occupied territories, especially Crimea, diplomatically, will be extremely hard to do.
And Ukraine without Crimea will always be exposed. It's too easy to choke off their maritime access without it.