Even as the British embassy in Tehran was attacked by demonstrators, Anthony Parsons urged the government in London to back the Shah as the "best hope for stability" in the country, according to files published at the end of a 30-year secrecy rule Tuesday.

In May 1978, ahead of a summer of protest against the Shah's rule, Parsons cabled: "My honest opinion is that the Pahlavis, father and son, have a good chance and my guess is that they will make it."

As the situation deteriorated, culminating in violent street protests, deaths and attacks on foreign embassies, the ambassador wrote, in early November, 1978, that the Shah had "recovered his morale."

"He (the Shah) was prepared to examine every feature of the abyss with admirable calmness and objectivity," reported the diplomat.

The papers showed that Parsons was reluctant to advise British citizens to leave Iran in the weeks leading up to the Shah's overthrow in mid-January, 1979.

Parsons, who went on to become Britain's ambassador at the United Nations, and who wrote a book about the fall of the Shah, died in 1996.