UN envoy Giandomenico Picco, who helped end the Iran-Iraq war and won hostage releases, has died

Former U.N. diplomat Giandomenico Picco, whose negotiating skills helped resolve some of the thorniest crises of the 1980s and 1990s, including the Iran-Iraq war and the kidnappings of Westerners by Hezbollah in Lebanon, has died.

Picco passed away peacefully Sunday after a long illness, his son, Giacomo Picco, said. He was 75.

Picco worked at the United Nations from 1973 until 1992. Javier Pérez de Cuéllar of Peru, the fifth secretary-general of the world body, appointed him to his executive office in 1982, and he eventually became assistant secretary-general for political affairs.

Picco represented Pérez de Cuéllar in negotiations between New Zealand and France after the Greenpeace flagship Rainbow Warrior was sunk by French secret agents in 1985. At the time of its sinking, the vessel was protesting French nuclear tests in the Pacific.

The following year, he became the chief U.N. official in charge of negotiating the truce in the war between Sunni-majority Iraq and Shiite-majority Iran. More than 1 million people were killed in the conflict that began when Iraqi dictator Saddam Hussein invaded his neighbor in 1980 and featured trench warfare, waves of attacks by Iranians and chemical weapons assaults by Iraq.

Picco also played a role in Afghanistan, helping facilitate the 1989 withdrawal of Soviet forces after Moscow’s 1979 invasion of that country.

Picco’s understanding of and relations with Iran allowed him to negotiate the release of hostages kidnapped by groups with ties to the Islamic Republic, including Terry Anderson, the bureau chief in Beirut for The Associated Press, who was held the longest — from 1985 to 1991.

The mission was not without risk. In 1987, Anglican church envoy Terry Waite disappeared from Beirut