The Ethics Of Bombing Dresden

This study describes the events, doctrine, and technical developments of World War II (WWII) that led to the destruction by area bombing of the city of Dresden and the deaths of 135,000 of its citizens. Prior to our entry into WWII our bombing strategy was to employ large numbers of high altitude bombers with heavy defensive firepower, flying in formation, using precision daylight bombardment. This ethical bombing technique was observed early on in WWII, but at some point the ethic changed. Why?