Kofi Annan of Ghana, whose popular and influential reign as secretary general of the United Nations was marred by White House anger at his opposition to the American invasion of Iraq in the early 2000s, died Aug. 18 at a hospital in Bern, Switzerland. He was 80. The death was announced by the Annan family and the Kofi Annan Foundation. The cause was not immediately disclosed. Current U.N. Secretary General António Guterres called Mr. Annan “a guiding force for good,” and added: “He provided people everywhere with a space for dialogue, a place for problem-solving and a path to a better world.” Mr. Annan, who pronounced his last name ANN-un to rhyme with “cannon,” shared the 2001 Nobel Peace Prize with the international body he led from 1997 to 2006. He owed his original triumph and his later turmoil to tense relations with the United States, but in some ways, he was an accidental secretary general...