Nathaniel Davis was born in Cambridge, Mass., on April 12, 1925. His father, Harvey, was a Harvard professor; his mother, the former Alice Rohde, was a research medical doctor. He graduated from Brown, served in the Navy Reserve and earned master’s and doctorate degrees from the Fletcher School of Law and Diplomacy.
He joined the Foreign Service in 1947 and served in Prague; Florence, Italy; Rome; and Moscow. He became first secretary in the embassy in Venezuela in 1960, and two years later was sent to administer the first Peace Corps volunteers in Chile. He returned to Washington to help R. Sargent Shriver organize the Peace Corps, which had been established by President John F. Kennedy.
Mr. Davis’s first ambassadorship was to Bulgaria in 1965. After two years, he joined the National Security Council to oversee Soviet and East European matters. In 1968 he was named ambassador to Guatemala, succeeding John Gordon Mein, who had been assassinated by terrorists.
Mr. Davis was sent to Chile 11 months before the coup with instructions “not to involve ourselves in any way,” Mr. Kissinger wrote in his memoirs.
Little more than a month after the coup, Mr. Davis was promoted to director general of the Foreign Service in Washington.
Mr. Kissinger chose Mr. Davis to head African diplomacy in 1975. His lack of experience with the continent prompted Africans, American blacks, editorialists and even Mr. Davis himself to question the appointment.
He resigned several months after questioning the wisdom of aiding anti-Communist forces. Roger Morris, in “Uncertain Greatness: Henry Kissinger and American Foreign Policy” (1977), quoted an unidentified official as speculating that Mr. Davis wanted to protect his career from “one Chile too many.”
Mr. Davis was soon appointed ambassador to Switzerland.
He became diplomat in residence at the Naval War College in 1977, and stayed there until 1983. He then became a professor of humanities at Harvey Mudd College in Claremont, Calif., retiring in 2002.
Mr. Davis was active in the civil rights movement and in the Democratic Party. He was also an experienced mountain climber. In 1995 he wrote a history of the Russian Orthodox Church called “A Long Walk to Church.”
In addition to his wife, the former Elizabeth Kirkbride Creese, Mr. Davis is survived by his daughters, Margaret Davis Mainardi and Helen Miller Davis; his sons, James Creese Davis and Thomas Rohde Davis; eight grandchildren; two great-granddaughters; and two sisters.