Well, pure self-interest would probably fall outside of morality, but one could make an argument that many conscriped ISIS fighters, US soldiers, and perhaps US leaders are acting out of self-interest.
https://en.wikipedia.org/wiki/Psychological_egoism#Circulari...
In cases like extreme nationalism, the zealot has essentialized the nation-state into their identity and is thus acting in their 'self-interest'. If one defines self-interest as interest in the health and reproduction of the body, then humans are emphatically not drive solely by self-interest.