TEHRAN, Iran - After an exuberant campaign season, voters across this country of 70 million headed to the polls today in a fiercely contested presidential election with potentially broad domestic and international repercussions.

Washington and capitals around the world are tensely anticipating the outcome of the vote, which pits incumbent Mahmoud Ahmadinejad against reformist Mir-Hossein Mousavi and two other challengers. The Islamic Republic and the West are at odds over Iran's nuclear program and support of extremist groups that oppose Israel. Pro-American Arab leaders have decried Iran's rising ambitions.

The next president, analysts say, will play a key role in forming Iran's response to the Obama administration's offer of comprehensive talks after a 30-year cold war between Tehran and Washington.

"There's a hope that if Ahmadinejad is not reelected this might facilitate engagement with Iran, specifically on the nuclear issue," said Ali Reza Nader, an analyst at the Rand Corp. "Ahmadinejad's rhetoric and style have an effect on U.S.-Iran engagement. Mousavi is seen as an easier candidate to deal with by certain segments of the [U.S.] foreign-policy establishment."

For Iranian voters, the election has emerged as a referendum on Ahmadinejad, pitting those who support his populist economic policies and fiery posture against those angered by his conservative social policies and his perceived damaging of Iran's relations with the West.

Polling numbers are scarce and unreliable. Ahmadinejad supporters say he will clobber Mousavi, his chief challenger. Mousavi's supporters say their polls show Ahmadinejad will lose by a double-digit margin.

Results will largely hinge on turnout among eligible voters, estimated at 46.2 million. The more people who vote, the better Mousavi's chances, analysts say. The poor and pious and rural voters who favor Ahmadinejad for his populist giveaways and low-interest loan policies tend to dutifully wait in long lines at the polls. The young, educated middle class who oppose Ahmadinejad tend to stay home or get discouraged by the slow process.

Election officials are planning for a record turnout, placing ballot boxes in 130 countries, including Iraq and the United States.

If Ahmadinejad is reelected, the West will look hard to see whether his government is prepared to tone down its rhetoric and enter into talks over Iran's nuclear program.

"Ahmadinejad says: 'Come here and let's debate. Let's argue,' " said Ahmad Bakhshayeshi, a political scientist and supporter of conservative candidate Mohsen Rezai. "But the U.S. isn't going to debate anything with us. Mousavi, on the other hand, wants to negotiate."

If Mousavi wins, many wonder whether Supreme Leader Ali Khamenei will give him leeway to broker a deal with the West. Khamenei wields ultimate authority over critical matters of state, such as the nuclear program.

Regardless of the outcome, the raucous campaign has unleashed new forces into the Islamic Republic. Deep fissures within the establishment emerged in televised debates among the candidates. Thousands of young and old poured into the streets to voice displeasure with the policies of Ahmadinejad.

"It will be interesting to see how it will evolve after the election, or how it will be suppressed," said Ali Akbar Mahdi, professor emeritus of social science at Ohio Wesleyan University.

The clashes between the titans have drawn ordinary people into debates about nuclear energy, the Arab-Israeli conflict, and relations with the United States.

"These are signs of the growth and health of our Islamic democracy," said Mohammad-Kazem Anbarlui, editor of the pro-Ahmadinejad newspaper Resalat. "It's not who runs in an election that counts. It's who participates."

Iran Rejects Appeal From U.N.

Iran has rebuffed a bid from the U.N. nuclear-monitoring agency to beef up its monitoring ability at an atomic site as the agency tries to keep track of the country's uranium- enrichment capabilities.

Diplomats said yesterday that Iran had turned down the request from the International Atomic Energy Agency to place one or more additional surveillance cameras at the Natanz enrichment site.

The diplomats said that Iran could reconsider and that talks continued. They asked for anonymity because their information was confidential.

Iran's refusal is troubling

at a time of the country's rapid expansion in uranium-enriching machines and the ability to produce material that could be upgraded into weapons-grade uranium.

A recent IAEA report said nearly 5,000 centrifuges were now enriching at Natanz, about 1,000 more than at the time of the last report, in February.

- Associated Press

EndText