You mean, like in Kosovo? Wasn't the West's main excuse to steal Kosovo from Serbia that most of the population was of Albanian origin? I fail to see how the West, having set such a precedent, can justify that Crimea is such an integral part of Ukraine, when most of its inhabitants are Russian.
But this is not about justice, fairness or anything. This is just hardcore geopolitics. Done in the same childish and short-sighted way as always. Putting fanatics in power in a Russia-satellite country to piss off the Russians... when have you last heard of such a move? Let me give you a hint, it usually blows right back in your face.