These days, it is rare to see any seriously argued articles about the role of ultra-nationalism on the Kiev-side of the Ukrainian civil war (that's right - it is now a full-blown civil war). But here is a very good article on the subject published in highly reputable and usually highly critical of Russia Foreign Affairs: http://www.foreignaffairs.com/articles/141405/alina-polyakova/on-the-march?sp_mid=45902074
It is objective, in my view, and it is factual. It does not assert that ultra-nationalism has a broad support in public opinion, but it does show that it is gaining ground and is one of the stronger forces behind the political leadership in modern 'Western' Ukraine.
