The most successful case of 1990s Irredentism is back in the news: Azerbaijan and Armenia are fighting again over the territory that Armenia took from Azerbaijan when the two fell out of the former Soviet Union. The key territory is Nargono-Karabakh, which was an enclave, more or less, within Azerbaijan, so Armenia not only claim N-K but also conquer territory that constitutes a bridge between N-K and itself. This conflict has been "frozen" since 1994, meaning that Armenia got to keep what it conquered but that it was not resolved. So, why unfreeze now?
Perhaps it is no surprise that the dynamics of irredentism would be similar to the dynamics of counter-irredentism. After all, efforts to bring back the lost territory today by Azerbaijan is irredentism, just as the effort twenty-five years ago by Armenia to take territory historically/ethnically seen as theirs. Folks have speculated that Azerbaijan may have re-kindled the flames here because its authoritarian regime might be facing some criticism/opposition at home. This may very much be an effort to rally around the flag. I am no Azeri expert, but it would not be hard to figure out the pattern of interests within Azerbaijan, the lack of concern about sacrificing international ties for a smidge of nationalist war, and the temptation to do what might be costly as long as the costs are not borne by those who have political influence.
Even if the Azeris started this round, the Armenians have a heap of responsibility in this stuff as the initial aggressor. However, they have better PR people so they should be ok.
Oh, and, by the way, that force for non-violence resolution of boundary conflicts, Russia, has been playing sides in this, mostly perhaps to foster arms sales. Russia probably has not caused this particular crisis, but it certainly has enjoyed playing both sides against each other since the early 1990s (yes, before Kosovo, before Libya, before Iraq, etc).
This conflict, of course, bears watching and not just because I want to sell more paperbacks. There is a heap of hyperbole about the consequences for the Caucuses. Not so sure about that, but it will be costly to those in harm's way.