It was the first change of sovereignty by force in Europe since the Second World War. A terrible precedent to set.
Is it your belief that the Crimean people should be forced against their will to live under the Ukrainian regime? You don't address the issues. Don't changes of sovereignty by force count if they are not in Europe and haven't you forgotten Yugoslavia? Afghanistan, Iraq, Libya plus the ongoing attempts to destabilise Iran, Venezuela, Russia, China to name but a handful. These don't count because they aren't in Europe?
I don't need to ask why you included such irrelevant and wrong parameters in your non answer. You are way out of your depth on geopolitics as you have demonstrated previously and are limited to repeating things that you have heard via a discredited media and state institutions. Western aggression against other countries is in front of your eyes and you refuse to see it. Russia's actions in the world cannot be credibly criticised by anyone who supports/condones the actions of the UK and its criminal cohorts on the world stage.