The story
From the novel The Ugly American (1958) by William Lederer and Eugene Burdick (though the character in the novel is only physically ugly and otherwise morally upright).
Etymology from Wiktionary, CC BY-SA 4.0.
ugly American
Today it means: An American government representative, tourist, or businessperson who, in dealing with people of other nations, is haughty, rude, meddlesome, chauvinistic, or jingoistic. Full definition →