One of the most evil things about war are the war damages that happen during it. Whole countrysides, cities, and lots of people can die. So I'd say the ravages of war are the most evil thing about war. Period.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
We escaped the ravages of war and evacuated into the countryside.