I can't be bothered working out the geopolitical history and intrigues of the Ukraine, Crimea and Russia: I have to 'fess up here, but if you draw a large circle centred on the western side of Ukraine, most of the countries caught in it have histories about which I can say next to nothing. Here, I'll even illustrate my personal zone of (pretty much) ignorance:
It's not that I even feel particularly guilty about this. With some regions of the world, say China, parts of South America, etc, I usually think it would be good to improve my knowledge of the history of the place, and maybe one day I will.
No, with Eastern Europe, with its ethnic mixes and 2500 year history of armies marching in one direction or the other across it, I've just always felt it is a place that is too far away, too complicated, and too difficult to be bothered understanding.
Now, people's interests change as they age, and if you have an eternity in which to increase knowledge, well, then pretty much everything can be interesting for a time. But so far, after 50 odd years or so, a desire to understand this part of the world has so far successfully eluded me.
Update: Oh look. I've found an interactive map of European history which, if I'm given 5 years to study, might start to diminish my ignorance of the Eastern parts in particular.
Update 2: the Sydney Morning Herald helps me at little, but mainly by confirming that I am not wrong when I say the history of Crimea is very, very complicated.