Answer:
The war events of 1939-1940 marked a significant deterioration of the norms of war, as a result of several developments that violated established rules and practices. Three examples of this deterioration are:
1. The bombing of civilian populations: During the early stages of World War II, both Germany and the Allies engaged in the bombing of civilian populations. The German Luftwaffe carried out devastating bombing campaigns against cities such as Warsaw, Rotterdam, and London, while the Allies bombed German cities such as Hamburg and Dresden. These bombings caused significant civilian casualties and destruction, and violated the established norms of war that prohibited attacks on non-combatants.
2. The use of chemical weapons: Both Germany and Japan used chemical weapons during the war, violating the norms established by the Geneva Protocol of 1925, which prohibited the use of chemical and biological weapons. Germany used poison gas in its extermination camps, while Japan used chemical weapons such as mustard gas and phosgene in its invasion of China.
3. The mistreatment of prisoners of war: During the war, both the Axis powers and the Allies mistreated prisoners of war, violating the norms of the Geneva Conventions that protected the rights of prisoners. The treatment of prisoners varied widely, but included forced labor, starvation, torture, and summary executions. The most egregious examples of mistreatment were the Nazi concentration camps and the Japanese prisoner-of-war camps, where prisoners were subjected to horrific conditions and mass extermination.
Overall, the war events of 1939-1940 marked a significant deterioration of the norms of war, as established rules and practices were violated on a large scale. The use of bombing campaigns against civilian populations, chemical weapons, and mistreatment of prisoners of war all contributed to this deterioration, and underscored the need for greater respect for international humanitarian law and human rights in times of conflict.