He raised the standing of the UN by his successful diplomacy in ending the Iran-Iraq War 1988 and securing the independence of Namibia 1989. He was a candidate in the 1995 presidential elections, but was defeated by his opponent Alberto Fujimori. A delegate to the first UN General Assembly 1946-47, he subsequently held several ambassadorial posts. He was unable to resolve the Gulf conflict resulting from Iraq's invasion of Kuwait 1990 before combat against Iran by the UN coalition began Jan 1991, but later in 1991 he negotiated the release of Western hostages held in Beirut.