A propos this, philosopher Jozef Müller (UC Riverside) kindly gave permission to share his interesting observations(I have not seen this point elsewhere):
I just read the post on your blog about the cause of Ukraine conflict (lecture by John Mearsheimer). One thing I keep somehow not seeing in the discussions, his including, is the issue of gas/oil which seems rather obvious to me. The former Soviet republics around the Caspian sea have large reserves and they have been trying to supply Europe without relying on Russia as a transport route (which it uses as a political leverage). Azerbaijan has recently succeeded – by the pipeline that goes through Georgia to Turkey and Turkmens want to join (but Russia is preventing the building of that connection through the Caspian sea – they also invaded Georgia at the time this pipeline was an issue I think). Russia has had to pay Ukraine for transport and it has been trying to circumvent it – Nordstream I and II, for example and it’s been squabbling over it with Ukraine for decades. However, Ukraine now has proved oil and gas reserves that it could sell to Europe on its own – with already some built infrastructure (see e.g. https://hir.harvard.edu/ukraine-energy-reserves/) but still in need of large investment. Much of it is in the Donbas region. This is, long term, a threat to Russia’s gas and oil business – it could significantly lower Europe’s dependence on it. So by annexing it, they get to control the future (or much of it) and they also get to cut their expenses to pay for transport of it to Europe. Given Russia’s dependence on gas and oil, this seems to me a pretty obvious motive (though I don’t want to claim the motive – probably there is a lot of causes).
Comments from informed readers welcome; they will, of course, be moderated for relevance!