“That treaty is called the 1994 Budapest Memorandum....”
This story could be spun either way. There are too many ambiguities. The Crimean Parliament doesn’t recognize the new Ukrainian govt. The new govt didn’t abide with the power sharing agreement from just days prior. Essentially it was a coup. The Crimeans are still loyal to Yanukovych and have always considered themselves Russians. They could easily rationalize that the new government is illegitimate, filled with extremists that would be oppressive to them. Yanukovych could say, he called on his allies (Russia) to protect his people from dangerous extremists trying to destabilize his country.
Just sayin...
No way Russia was ever going to give up on The Crimea. It was foolish to think otherwise.