Cycle of Revenge in WWII

A lot of atrocities were committed in WWII not only by the German but all sides of the war. WWII is one big cycle of revenge. It originally started as bombing pill boxes and enemy trenches but then someone got the idea to bomb factories and railroads. Some random guy said the enemy can't fight back if they have no people to fight with, so they started to bomb cities. Notice how I only said they and gave no names that's because this happened on all sides Germany, America, Britain, Japan everyone was bombing everyone and then it became about revenge. You bomb this city so I'm going to bomb your city. We only bombed that because you bombed this. It eventually got to the point where no one remembers what started the cycle.

NOTE I'm only talking about the bombing as a form of revenge not the entirety of WWII we know why it started