Blitzkrieg
Germany overran much of Europe and was victorious for more than two years by relying on a new military tactic called the "Blitzkrieg" lightning war. Blitzkrieg tactics required the concentration of offensive weapons such as: tanks, planes, and artillery, along a narrow front.
Kamikazes
The first successful Kamikaze attacks took place during the Battle of Levte Gulf, on 25 October 1944, just after the action off Samar. These attacks were ordered by Onishi Takijiro, who was initially opposed to suicide tactics.
The history of the British bombing campaign in World War Two shows us how easily war can erode moral standards. British descended into emeny level after bombing.