There certainly are reasons (not a value judgement), some of them cynical:
- Crimea wants to control the canal from the Djnepr, which had been shut off by Ukraine.
- Russia wants the coast line to control more gas fields in the Black Sea. The U.S. of course also want to control them by proxy (see Burisma/Biden). Snake island also controls some of the fields.
- Rightly or wrongly, Russia is scared of NATO expansion.
I think it may be the case that the great Russian empire theory is a pretext that is put forward by Putin for his own population and eagerly taken up by the West for propaganda. Attacks on Kyiv (stalled) and Kharkiv could be diversions from the south. As noted above, the Kharkiv attack does not make sense though.
The reasons for the immediate action might be logical, but looking at the medium term consequences it breaks down completely in my mind. The only two possibilities I can see going forward is either a forever-war as in Afghanistan, or a forever-sanction situation like Iran or DPRK.
I don't see how any listed benefits would outweigh the costs of either option. It troubles me a lot, because Putin has seemed to me to be a carefully calculating player up until this. It makes me wonder if he has truly lost it. Or if there is some grand plan which this is only a small part of. Both are scary.
- Crimea wants to control the canal from the Djnepr, which had been shut off by Ukraine.
- Russia wants the coast line to control more gas fields in the Black Sea. The U.S. of course also want to control them by proxy (see Burisma/Biden). Snake island also controls some of the fields.
- Rightly or wrongly, Russia is scared of NATO expansion.
I think it may be the case that the great Russian empire theory is a pretext that is put forward by Putin for his own population and eagerly taken up by the West for propaganda. Attacks on Kyiv (stalled) and Kharkiv could be diversions from the south. As noted above, the Kharkiv attack does not make sense though.