Foreign Affairs has the article Why the Ukraine Crisis Is the West’s Fault. The magazine won’t let me see the full article, but here is an excerpt from the part they let me read.
For Putin, the illegal overthrow of Ukraine’s democratically elected and pro-Russian president — which he rightly labeled a “coup” — was the final straw.
To see what part the USA played in the overthrow, look up Victoria Nuland on this blog.
Here is one link to an article you will find in the above search – U.S. officials caught in Ukraine plot.