World War I was a devastating war that made use of new, terrible technologies like machine guns, tanks, airplanes, and chemical weapons. It resulted in millions of deaths and contributed to the Russian Revolution and communist rule. World War II was also tremendously destructive, killing two-thirds of the world's population according to estimates, thanks to new technologies like the atomic bomb. Between the two world wars, modern architecture developed through new building materials and designs. Overall, the text discusses how modernism emerged as a rejection of tradition through landmarks like the world wars and their advanced weapons and the development of modern architecture.