No. Nationalism can lead to people performing evil actions, but nationalism in and of itself is not evil.
I would say that is the very definition of what makes an abstract concept evil, at least so long as there is no corresponding greater good that comes of it. And there is no corresponding greater good associated with nationalism.
As Supersoulty pointed out, there are incidents where nationalism can be good. Nationalism is simply a feeling, an emotion held towards one's nation. The reasons why that feeling is held will usually determine what kind of outcome you'll get - people are nationalistic usually because they agree with whatever ideals their state supports.
Poll
