Waldheim, Kurt, VALT hym, koort (1918-...), is an Austrian diplomat who served as secretary-general of the United Nations (UN) from 1972 to 1981. He replaced U Thant of Burma (now Myanmar). As secretary-general, Waldheim carried out several difficult peacekeeping missions. He failed to stop a war between China and Vietnam in 1979, though the fighting ended that same year. In 1980, Waldheim could not get the release of American hostages held in Iran. The Americans were freed in 1981. He also failed to end the Iran-Iraq War that began in 1980. A UN-arranged cease-fire halted the fighting in 1988, six years after he had stepped down as secretary-general.