Moldova had a population of ethnic Russians that lived on the Eastern bank of the river D'niest'r. (Similar to the Crimean region in Ukraine.)
Eventually a civil war broke out, and Russia stepped in to back the ethnically Russian region (sound familiar?). The end result was a stalemate. A ceasefire was declared in 1992, and the ethnically Russian region decided to spin off its own government. They call themselves Pre'd'niest'rovia (or Transnistria), and function as an entirely separate country from Moldova. That means different language (Russian, not Moldovan), currency, parliament, military, etc etc. Yet Moldova never accepted it as a sovereign country, and neither did the rest of the world.
To this day, when you see Moldova on a map you only see one country where really there are two.
What's happening in Ukraine today is almost a mirror image. I suspect it will result either in a similar two-country situation with one being unrecognized, or the Eastern half of Ukraine will form a new country.
PS - I was born in Transnistria and lived there until I was eight. Several months ago I went to visit for the first time since leaving 18 years ago. It's a miserable place to live. I also visited Kiev and Odessa (Ukraine) on the same trip, and am glad I did so before this violence broke out.