Perhaps it was the half-hearted chanting, the sheer psychological tiredness involved in screaming repeatedly "Death to America" for 16 years. The failure of many of the militiamen and army officers even to raise their arms in the same tired old gesture of defiance seemed to be in near collusion with the very few spectators. "Death to America, Death to Israel ..." and then, when they caught sight of a BBC crew, "Death to England". This was pantomime.
They took their places on the forecourt of Tehran university, the military in their divisions - a mass of air force blue in the middle, a brown rash of Basij militia behind, companies of mullahs at the front, a few children among them with hands upturned in prayer among the cries of ''Allahu Akbar''.
Friday prayers took place in a setting that Shakespeare would have understood. The congregation sits below two raised levels. The first, on the left, is a kind of proscenium upon which the BBC and CNN and Iranian state television and Reuters place their cameras, attendant lords to assist in a familiar drama. For just to the right of the podium is a smaller stage set into the wall, a kind of royal box lit by lights in which appeared yesterday the turbanned figure of President Ali Akbar Hashemi Rafsanjani.
The worshippers fell silent. What verbal javelins would be hurled today at the capital of "world arrogance", what threats uttered against "Zionism and all its works"? Mr Rafsanjani stood, sweating slightly under the camera lights. Many in the congregation were to be disappointed, for what he wanted to talk about was Iran's community progress, economic renewal and technological advance. He said that Iran's communications had improved dramatically - under the Shah, 800,000 telephones existed across the country; now there were 25 million lines.
What were the Revolutionary Guards thinking all this while? They had cried themselves hoarse for years, promising to humble the Great Satan of America. Yet here was Iran, allegedly facing an economic siege by the nation it had loathed for 16 years, and the response was a pat on the back for Iran Telecom. There were, it is true, a few obligatory references to Israel's continued occupation of the Palestinian West Bank, but these were delivered without emotion. And then Mr Rafsanjani came to the point. He must keep the Iranian riyal at 3,000 to the US dollar. In two years, this policy would bear fruit. In the meantime, businessmen would not be allowed to take advantage of Iran's $6bn in non-oil exports by using the black market. The black market - this, at least, was America's fault - would be broken. The new exchange rate would be kept until the end of the year. There was no doubt what has been dominating the president's mind this week.
Up on their own stage, the camera crews were growing restive; this was definitely not the reason they picked up their visas at Iranian embassies last week. They filmed the fidgeting soldiers and listened for the moment they were waiting for, the resumption of the half-hearted "Death to America" with which they could re-establish their medium's blind historical routine. Sure enough, they got their "Death to America", delivered with such lack of passion that some among the chanters smiled at the cameras.