Both previous post make valid points. To build upon those, you might consider that one must have a sense of patriotism in one's own country in order to recognize commonalities with others--to acknowledge the needs of humanity. I agree, however, that when this patriotism is allowed to run unchecked bad things happen. Fanaticism is a good description of this. Look at Hitler--the most horrific example of patriotism/fanaticism run amok.
Indeed, the previous post's assertion of patriotism morphing into nationalism is a compelling one. If nationalism is unchecked, it leads to fairly horrific elements because it is not content with national pride of one self, but rather seeks to expand this notion of pride into another nation's sovereignty or autonomy. I think that this particular item makes patriotism a concept where fear is evident and one that has to be approached with a level of sobriety and vigilance so that the right of one's nation to be proud of oneself does not extend into denying another nation the right to be left alone.