~ Gilbert Keith Chesterton, What I Saw in America, 1922
American Exceptionalism: A Double-Edged Sword (by quoting, in turn, Chesterton):
Born out of revolution, the United States is a country organized around an ideology which includes a set of dogmas about the nature of a good society. Americanism, as different people have pointed out, is an "ism" or ideology in the same way that communism or fascism or liberalism are isms. As G. K. Chesterton put it: ‘America is the only nation in the world that is founded on a creed. That creed is set forth with dogmatic and even theological lucidity in the Declaration of Independence.’ … The nation’s ideology can be described in five words: liberty, egalitarianism, individualism, populism, and laissez-faire. The revolutionary ideology which became the American Creed is liberalism in its eighteenth- and nineteenth-century meanings, as distinct from conservative Toryism, statist communitarianism, mercantilism, and noblesse oblige dominant in monarchical, state-church-formed cultures.
Other countries' senses of themselves are derived from a common history. Winston Churchill once gave vivid evidence to the difference between a national identity rooted in history and one defined by ideology in objecting to a proposal in 1940 to outlaw the anti-war Communist Party. In a speech in the House of Commons, Churchill said that as far as he knew, the Communist Party was composed of Englishmen and he did not fear an Englishman. In Europe, nationality is related to community, and thus one cannot become un-English or un-Swedish. Being an American, however, is an ideological commitment. It is not a matter of birth. Those who reject American values are un-American.