William H Sullivan, a veteran diplomat who oversaw the "secret war" in Laos, aided in negotiations to end US military involvement in Vietnam and was the last American ambassador to Iran, has died the age of 90.
Sullivan died Oct 11 at an assisted-living facility in Washington, according to his daughter, Anne Sullivan.
As ambassador to Laos, William Sullivan controlled a secret US bombing campaign against North Vietnamese troops moving through Laotian territory along the Ho Chi Minh trail.
His daughter said he required that he approve all bombing runs, in an effort to limit civilian casualties and armed conflict in Laos.
William Sullivan played an important role in initiating the opening of discussions with the North Vietnamese that led to the Paris peace talks.
As a deputy to Henry Kissinger, who was President Richard's national security adviser, Sullivan spent months helping coordinate the talks to extricate the US from the Vietnam war.
Sullivan then served as ambassador to the Philippines and helped coordinate the arrival and eventual resettlement of thousands of Vietnamese refugees after the fall of Saigon in 1975.
He was named ambassador to Iran in 1977 by President Jimmy Carter at a time that restive Iranians were growing tired of the rule of Shah Mohammed Reza Pahlavi.
In 1979, Sullivan was instructed to tell the shah that the United States felt he should leave Iran.
Ayatollah Khomeini, the exiled revolutionary leader, returned to Iran in early 1979, and revolutionary forces toppled the monarchy.
Several days later, heavily armed guerrillas attacked the US Embassy.
Sullivan directed the defense of the embassy and ordered Marines to use tear gas to keep the attackers out while staff destroyed files and equipment.
The attackers captured Sullivan and about 100 other Americans and they were briefly held hostage, but pro-Khomeini forces were able to gain control of the embassy from the attackers.
Sullivan left Iran soon afterward and retired from the Foreign Service later in 1979. Sullivan's experience as a hostage in Iran came nine months before the seizure of hostages at the US Embassy that lasted from November 1979 until the end of the Carter presidency on Jan. 20, 1981.