Not quite a war quote, but I loved this ditty from the commisar near the end.
'I've been such a fool, Vassili. Man will always be man. There is no new man. We worked so hard to create a society that was equal, where there'd be nothing to envy your neighbour. But there's always something to envy. A smile, a friendship, something you don't have and want to appropriate. In this world, even a Soviet one, there will always be rich and poor. Rich in gifts, poor in gifts. Rich in love, poor in love.'
-Danilov, Enemy at the Gates