Your view of history is far from accurate. The "vote" by crimea to leave ukraine was after Russia took over Ukraine in a military action. Voting to secede after someone takes you over and that Russian someone doesn't do democratic voting.

From Wikipedia - https://en.wikipedia.org/wiki/2014_Crimean_status_referendum

"The Crimean status referendum of 2014 was a disputed referendum[1][2] on March 16, 2014, concerning the status of Crimea that was conducted in the Autonomous Republic of Crimea and the city of Sevastopol (both subdivisions of Ukraine) after Russian forces seized control of Crimea.[3]"

I think you have the order of events there a little jumbled, brother.

Little hard to have a fair vote with little green men standing outside the polls.