The competition among Western powers heated up in the second half of the nineteenth century and spilled over into the early twentieth. Competition for power and resistance to existing structures contributed to the violence, and the use of industrial technology in warfare made conflicts more destructive than ever. As these imperial contests expanded and developed into revolutions, local wars, and eventually, world war, the death and destruction felt around the world arrived at a scale not before seen. World War I provided as many innovations on the battlefield and home front as lives lost, and the postwar process of making peace did relatively little to solve the general issues that led to the outbreak of war. The World War did further the development of mass society and culture, and leveled social classes on the battlefield, but many of the developments became key ingredients in politicians’ efforts to recruit supporters and lead to further mobilization. Outside of Europe, some societies were able to flourish, such as that of Argentina, examined in the Counterpoint of this chapter, which experienced a “golden age” in stark contrast to the suffering elsewhere.