I've probably mentioned this before, but I'd recommend the novel "The Devil's Alternative" by Frederick Forsyth for anyone interested in the topic of Ukrainian separatists taking on the Soviet Union.
It's set in the 1980's. Long story short, British and Canadian citizens of Ukrainian descent ally with Ukrainian separatists inside the Ukraine in an attempt to assasinate the Chairman of the KGB when he's visiting (I think) Kiev.
The leader of the group outside the Ukraine is the son of a Cossack who surrendered to the British after World War 2 and managed to avoid being deported to the Soviet Union (I think by getting a British woman pregnant - it's been a while since I read it, although I do recall that the author goes into a fair bit of detail on the character's background).
Here's a link to the wiki entry (which does have a number of plot spoilers)
http://en.wikipedia.org/wiki/The_Devil's_Alternative