Events leading up to World War 2 There have been many leading causes that have lead up to World War 2. The Second World War is the most important period of the 20th century. It brought about major advances in technology and it permitted postwar social changes such as the women’s rights movement, civil rights movement in the U.S. and programs for exploring outer space. The axis nations and the allied nations were the countries that were involved in this war. World War 2 started on July 7, 1937, when
that these principles are necessary for war to be considered just. Furthermore, is it possible to apply these jus ad bellum principles to an unconventional war, such as the United States’ interactions with the Middle East since the 2001 terrorist attacks? Without a clear cut war to base these principles off, it is not possible to apply the jus ad bellum principles to unconventional warfare interactions.