Additionally the Kosovo constitution offered room for secession and it's secession was consequently recognized by the vast majority of the international community.
The votes on the UN council as to the legality of Russia's actions [1] say enough, but Huffinton Post wrote a fairly comprehensive article [2] about the topic.
P.S. If you plan to link to the RT counter-piece [3] just let me know and I'll list all the factual inaccuracies for you.
[1] http://www.thegatewaypundit.com/wp-content/uploads/2014/03/u...
[2] http://www.huffingtonpost.com/david-l-phillips/crimea-is-not...
[3] http://rt.com/news/kosovo-crimea-referendum-recognition-441/