Part of it is trying to keep up morale. If you feel so beaten down that you won’t do anything, that’s just as bad. Not everyone can get motivated from the bleakness of a situation or from difficult and almost impossible struggle. For those of us who are, it feels like finally we’re fighting some actual great evil, of whose evilness justifies ANY means of defeating it. It feels exciting for us, I’m guessing it almost like a form of that bloodlust that those who get captured by the enamoring power of war feel when their country declares it upon another country which they view as evil.