Ukraine – Is Russia to Blame?

According to the Budapest Memorandum of 1994, Russia, the US, and the UK confirmed, in recognition of Ukraine becoming party to the Treaty on the Non-Proliferation of Nuclear Weapons and in effect abandoning its nuclear arsenal to Russia, that they would: respect Ukrainian independence and sovereignty within its existing borders; refrain from the threat or use of force against Ukraine; and also refrain from using economic pressure on Ukraine in order to influence its politics. Have they breached an agreement they themselves agreed to? Can Russia deploy the argument of supporting self-determination and democratic will without jeopardizing the perhaps more important principle of national sovereignty? We speak about the crisis in Ukraine and the threat of a Second Cold War.