Bombing of German cities, followed bombing of British civilian area, such as London.
Hamburg, Dresden, Berlin (and other cities, too) were bombed for "good reason;" winning the war the Germans started.
I served during the Cold War in one of the medium sized industrial cities, which was bombed several times. Leveled. They made and transported military goods during WWII.
(Now they build high end aluminium Audis there).
It is easy after the fact of war, for leftists, crybabies, do-gooders, to bemoan how a war could have been conducted more humanely.