eeePart 1: Anti-Missile and nuclear weapons on the border are 99% of why Europe has been so stable for the past 70 years. Trying to blame outside pressure for Russian expansionism seems a bit silly.
Mutually Assured Destruction is what kept Europe and the world safe during the cold war. Since the fall of the Berlin wall NATO has been expanding eastwards in an attempt to nullify the threat of Russias nuclear arsenal. That's what has them upset, it's what they have been saying is upsetting them for the past decade or more. NATO is trying to engineer a situation in which a Russia would not be able to respond to a nuclear attack on it's country because there are NATO missile defence weapons completely surrounding them.
Upsetting the balance of power is exactly what has caused the current tensions with Russia. It's not in their interests to let Ukraine become a part of the EU and join NATO as it means NATO troops and missiles on their border hence why they are supporting the separatists and invaded Crimea (NATO rules prevent members with border disputes from joining the alliance). Just imagine the shit fit USA would throw if Canada or Mexico decided to host Russian nukes. Or the shit fit the USA did throw when Cuba tried to.