The American Century is a characterization of the period since the middle of the 20th century as being largely dominated by the United States in political, economic, and cultural terms. It is comparable to the description of the period 1815–1914 as Britain's Imperial Century. The United States' influence grew throughout the 20th century, but became especially dominant after the end of World War II, when only two superpowers remained, the United States and the Soviet Union. After the dissolution of the Soviet Union in 1991, the United States remained the world's only superpower, and became the hegemon, or what some have termed a hyperpower. Origin of the phrase The term was coined by Time publisher Henry Luce to describe what he thought the role of the United States would be and should be during the 20th century. Luce, the son of a missionary, in a February 17, 1941 Life magazine editorial urged the United States to forsake isolationism for a missionary's role, acting as the world's Good Samaritan and spreading democracy. He called upon the US to enter World War II to defend democratic values: Democracy and other American ideals would "do their mysterious work of lifting the life of mankind from the level of the beasts to what the Psalmist called a little lower than the angels". Only under the American Century can the world "come to life in any nobility of health and vigor". According to David Harvey, Luce believed "the power conferred was global and universal rather than territorially specific, so Luce preferred to talk of an American century rather than an empire". In the same article he called upon United States "to exert upon the world the full impact of our influence, for such purposes as we see fit and by such means as we see fit". Early characteristics Beginning at the end of the 19th century, with the Spanish–American War in 1898 and the Boxer Rebellion, the United States began to play a more prominent role in the world beyond the North American continent. The government adopted protectionism after the Spanish–American War to develop its native industry and built up the navy, the "Great White Fleet". When Theodore Roosevelt became president in 1901, he accelerated a foreign policy shift away from isolationism and towards foreign involvement, a process which had begun under his predecessor William McKinley. For instance, the United States fought the Philippine–American War