In fact, the temperature is dropping over Iran’s controversial nuclear program and the anti-Israeli invective of Mahmoud Ahmadinejad, the country’s ultraconservative new president.

From the first, Ahmadinejad was off on the wrong foot with Washington. Five of the 66 people seized by militant Iranian students in November 1979 — 52 of whom were held until the end of the hostage drama 444 days later — claimed that Ahmadinejad had been one of their captors.

Analysis of photographs taken at the time quickly disproved this, but nonetheless, it set the tone and provoked official reaction.

Washington broke off diplomatic relations with Tehran on April 7, 1980, five months after the embassy was seized by the students, whose demands included the extradition of Mohammad Reza Pahlavi, Iran’s deposed, US-backed shah.

Ahmadinejad, for his part, has not sought friendly relations with Washington.

"That will never be, nor can ever be," he said during his election campaign. "I never spoke of ties with the USA. As you know, those who did lost the election.

Ahmadinejad was referring to former Iranian president Akbar Hashemi Rafsanjani, the pre-election favorite.

The US administration sees what it calls Iran’s "regime" as a "recalcitrant" actor in its plans for democratization of the Middle East. In his most recent public address, US President George W.

Bush described Iran as the world’s largest state sponsor of terrorism, and accused it of seeking to build nuclear weapons while denying the Iranian people the freedoms they deserved.

According to the US State Department, there are a number of other obstacles in the way of better relations, including Iran’s opposition to the Mideast peace process, human rights violations, and Iran’s current role in Iraq.

On top of that, Ahmadinejad’s anti-Israeli outbursts — he called for Israel to be wiped off the map and said the Holocaust was a myth — have caused outrage in the United States, whose chief Mideast ally is Israel.

There have been moments of hope for better US-Iranian relations during the past quarter-century. After Rafsanjani became president in August 1989 two months after the death of Iran’s revolutionary leader Ayatollah Ruhollah Khomeini, Teheran looked to improve ties with the "Great Satan" — the United States.

But Iran’s leaders sensed little reciprocation. They felt, for example, that their help in effecting the release of American hostages in Lebanon in the early 1990s was insufficiently appreciated.

"We did a lot of things, but the signals we hoped for from Washington never came," Rafsanjani said.

In January 1998, then president Mohammad Khatami made another attempt. Speaking to the US television network CNN, Khatami apologized for the 1979 hostage-taking to the US people — though not to the US government — and called for improved relations at least in the areas of science, culture and sport.

Khatami’s initiative brought a short-lived relaxation of tensions, but not the breakthrough that Teheran had wished.

In 1995, then US president Bill Clinton imposed economic sanctions against Iran for its alleged involvement in terrorism. US exports to Iran today are limited to food and medicine. In addition, the United States has excluded Iran from lucrative regional projects such as pipelines meant to deliver oil and natural gas to the West via Turkey.

All attempts at rapprochement ended in early 2002, when Bush termed Iran — along with North Korea and Saddam Hussein’s Iraq — a "rogue state" and member of the "axis of evil." After that, Khatami, too, hardened his stance toward Washington.

"Once again, efforts (at improved relations) turned out to be a Sisyphean task," commented a European diplomat in the Iranian capital.

As the irony of fate would have it, Abbas Abdi, a leading Iranian journalist and leader of the 1979 hostage-takers, was imprisoned for 30 months in connection with a 2002 opinion poll in which over 75 per cent of the respondents were in favor of resuming diplomatic ties with Washington.

The results of the survey called into question a central tenet of Iranian foreign policy for the past quarter-century, and Abdi was charged with "propaganda" against the state.