Russia's Rights to Former Soviet Lands

I am a child of the 80s. I grew up seeing Russia as a tricky aggressor. I have certainly never trusted them since the wall fell. 

However, I continue to think that the US is stirring this war and inciting Russia to make its territorial claims. In addition, news articles I find continue to support this view. 

I don't usually take articles from the Huffington Post, but this one caught my eye. If former President George Bush (the first) stated that we would not accept Eastern Block nations into NATO, and we certainly have, then in my mind it seems this verbal contract has been broken. Russia took down the wall and we weren't supposed to incorporate its parts into Western agreements, then we should't have. 

This seems like we are making an act of aggression against Russia and Russia is responding in kind. Since we were so willing to let the Eastern block nations into NATO, and then turned our eyes to allowing Georgia into it, of course Russia is going to occupy Georgia to prevent that. Now we are trying to let Ukraine into the organization and so Russia is again protecting its interests. 

Why do we have to do this? Why can't we leave them alone? If we continue to focus on bringing former Soviet satellites into NATO we should only expect Russia to react by strengthening its hold in these countries.