In interviews in his own defense, Mr. Aziz said that no one had ever accused him specifically. And his defense lawyers asserted that he had been responsible only for Iraq’s diplomatic and political relations — that he had had no ties to the executions and purges carried out by Mr. Hussein’s government.

Even some who became opponents of Mr. Hussein’s government defended Mr. Aziz. Hassan al-Alawi, who was a senior Baath Party member when Mr. Hussein took power but who later fled into exile and then returned after the United States invasion, described the death sentence against Mr. Aziz as payback — a “retaliatory” gesture for his role as foreign minister in gathering international support for Iraq during the Iran-Iraq war.

“Mr. Aziz is innocent, and the death sentence was unfair,” Mr. Alawi said.

He said he believed that the authorities had not carried out the sentence knowing that Mr. Aziz was sick and likely to die in jail.

In the early days of the Hussein government, Mr. Aziz had relatively good relations with the United States, serving as a buffer between his government and the Reagan administration as it sought to navigate the twists and turns in the Iraqi-American relationship. American relations with Iraq were far closer after the Iranian revolution in 1979 than they were by 1990, after President George Bush had entered the White House.

Before the first American-led invasion of Iraq in 1991, Mr. Aziz tried to justify Iraq’s invasion of Kuwait in 1990, saying that it resulted from a failure by Kuwait to reduce oil production and that it appealed to Arab nationalist sentiment.

Kuwait’s increased production was bringing down oil prices, he said, costing Iraq billions of dollars every year. The Iraqis, he said, viewed that as part of a conspiracy to damage their country.