The internal issues of former Soviet republics, you see, are not truly internal issues of sovereign nations. This is because, by Stalin’s very conscious design and very deliberate border drawing and population movement, most former Soviet republics are ethnic hodgepodges. So Ukraine has a sizable Russian population. Ditto Estonia, ditto Georgia, ditto Kazakhstan. And, according to Putin’s unspoken doctrine, anywhere Russian citizens are determined to be at risk, Mother Moscow can intercede with force on their behalf.
Worth a read. The current Ukraine crisis is crazy complex and TV reporting seem more focused on what Obama might do rather than what the facts on the ground are.