Examine the causes, events, and consequences of the three major conflicts of the 20th century: World War I (1914-1918), World War II (1939-1945), and the Cold War (1945-1991). Examine the relationship of war to various aspects of society; these include ideologies, political systems, political and cultural movements, economic revolutions, politico-economic structures, and technological advancements. Identify some of the great political and military thinkers and leaders of the period.