WORLD WAR II, the name commonly given to the global conflict of 1939-1945. It was the greatest and most destructive war in history. Whereas military operations in World War I were conducted primarily on the European continent, World War II included gigantic struggles not only in Europe but in Asia, Africa, and the far-flung islands of the Pacific as well. More than 17 million members of the armed forces of the various belligerents perished during the conflict. Its conduct strained the economic capabilities of the major nations and left many countries on the edge of collapse.