If an identifiable geographic region wants to secede, and there is sufficient support among the public, it should be able to do so. Crimea I think falls into that group: 93% voting in favor of joining Russia with 83% turnout.

I think there needs to be more than just a geographic region. A people have a right to self-determination. I'm not sure if any group of persons should. You need to look at history, ethnicity, language, culture, etc.

Fair point.

How does it fall in that group? That's a referendum taken out of the blue, just weeks after Russian military takeover of the region.