The Shiite holy cities of Najaf and Karbala are back in business - teeming with thousands of pilgrims drawn from across the Middle East and Asia.
After decades of persecution by Saddam Hussein's regime, the Shiite resurgence in these two holy cities presents new opportunity - and a potential challenge - for the Shiite leadership in neighboring Iran.
Amid preparations for pivotal elections Friday in Iran - and later this year in Iraq - analysts see two Shiite visions of democracy vying for dominance. Some say the traditionally "quietist" clergy represented by Iraq's Grand Ayatollah Ali al-Sistani is growing more influential at the expense of Iran's all-embracing system of clerical rule embodied by Iran's Ayatollah Ali Khamenei.
"There is a strong possibility that over time large numbers of lay religious Iranians will switch their allegiance to Sistani, and some of the [Iranian] reformers are said already to have done so," says Juan Cole, professor of history at the University of Michigan and a specialist in Shiite affairs. "But the Khamenei establishment is extremely wealthy and offers scholarships, so the seminarians and clerics in Iran would have difficulty defecting en masse. Sistani does not have nearly as many monetary resources."
But Khamenei faces other, nonfinancial challenges. The powerful ruling clergy in Iran is under attack from a growing number of Iranians frustrated at the faltering attempts to achieve greater openness and political freedom.
Reformist efforts were dealt a blow in the run-up to Friday's parliamentary elections in Iran when some 2,400 mainly opposition candidates were barred from competing.
Iran's Wilayet al-Faqih doctrine (governance of the religious jurist, preached in the Iranian city of Qom) was devised in the mid-1970s by Ayatollah Ruhollah Khomeini and served as the ideological underpinning of the 1979 Islamic Revolution in Iran which he led. It grants absolute authority over all matters - religious, social, and political - to a marja who has earned the title of mujtahid, a blend of judge and theologian.
Although the Wilayat al-Faqih system was successfully introduced into Iran's homogenous Shiite society, exporting the doctrine elsewhere has proved difficult.
Its most successful adaptation outside Iran is by Lebanon's Hizbullah organization which considered Khomeini and then his successor Ayatollah Ali Khameini as the group's marja. Establishing an Islamic state in Lebanon on the Iranian model remains one of Hizbullah's ideological goals, on paper at least. But Hizbullah long ago accepted that the tiny country's multiconfessional character mitigates heavily against the creation of an Islamic state.
So, too, with Iraq. Iraqi Shiites represent around 60 percent of the population. The remaining 40 percent is comprised of Sunni Muslims, several Christian sects and a tiny Jewish community. Furthermore, many Shiites are avowedly secular and have little enthusiasm for an Islamic state, whether governed by Wilayet al-Faqih or a less comprehensive form of Islamic rule.
Even groups such as the Supreme Council for the Islamic Revolution in Iraq (SCIRI), which was supported by Iran during Saddam Hussein's regime, has begun to distance itself from Tehran's clerical rulers to boost its appeal among Iraqi Shiites.
"The Iranians have their own problems and that is not a model for us," says Sheikh Humum Hammoudi, a senior member of SCIRI's leadership. "We want our religious leaders to be advisers not [political] authorities."
The question of Iraq's political future is due to come to head in the months to come. Despite uncertainty surrounding the nature of the country's upcoming elections, the US is expected to hand over power to an Iraqi government by June 30.
"Changes are possible but the date holds," Iraqi administrator Paul Bremer told reporters Thursday. Bremer spoke before an expected announcement by UN Secretary-General Kofi Annan. Mr. Annan was expected to say that elections are important but that they cannot be held by the end of June.
A rare insight into Sistani's views on Iran's Wilayet al-Faqih system was posted on the Internet last week by an anonymous Sunni tribal leader who met with the reclusive Shiite cleric at his home in Najaf.
"He does not believe in 'Wilayat al Faqeeh' as the clergy in Iran do.... He repeatedly stressed that religion has to be separated from government," the letter said. "He said that he firmly believed that the clergy should not interfere with the running of people's lives, with government or with administration. He had forbidden his followers from putting their noses into the state's affairs. He said that clearly and categorically (several times to stress the point!)"
According to Sheikh Jalaleddine as-Saghir, Sistani's representative in Baghdad, the ayatollah recommends a multisectarian government for Iraq.
"He suggests that the government should represent all Iraqis," he says. "The Iraqi people should be the marja of the Iraqi government."
As for the future constitution, Sistani favors one that does not contradict sharia (Islamic) law but is not derived from it, Sheikh as-Saghir says.
Yet Sistani does not speak for all Shiite clerics. The Wilayet al-Faqih system is embraced in Iraq by followers of Mohammed Baqr al-Sadr and Mohammed Sadeq al-Sadr, two prominent clerics who were killed in 1980 and 1999 respectively for defying Mr. Hussein's regime.
"Of course, there is much sympathy for the Wilayet al-Faqih among the Shiites because the two Sadr martyrs called for it and both died for their beliefs," says Sheikh Hamzi al-Tai, who heads the Kerbala office of Moqtada al-Sadr, a young extremist cleric and son of Mohammed Sadeq al-Sadr.
Nonetheless, few believe that the Wilayet al-Faqih system has enduring appeal to Iraqi Shiites.
"Apart from Mohammed Baqr al-Sadr, no one in Najaf agreed with Khom- eini's Wilayet al-Faqih," says Jaber Habib, a professor of politics at Baghdad University. "There's no great challenge from Moqtada al-Sadr as most Iraqis follow Sistani. Moqtada has support only because of his father. He is not a marja and is not advanced in religious studies. He is a flash in the pan."
Other than ideological differences, the Sadrists also harbor suspicions of Sistani's Iranian background - he speaks Arabic with a thick Persian accent. Many senior clerics in Najaf are of Iranian descent, whereas the Sadrs are Arabs of Iraqi-Lebanese origin.
Distrust of Iranian marja appears to have been behind the killing on April 10 last year of Ayatollah Abdul Majid al-Khoei, son of a noted Iranian scholar who returned to Iraq from exile in England and was stabbed to death in the Imam Ali shrine in Najaf. Followers of Moqtada Sadr have been blamed for the murder, and there are fears that Sistani could be next.
"As a Muslim, Sistani has a right to ask for the rights of Muslims. But he does not have a right to interfere in the affairs of Iraq," says Sheikh Tai. "We won't cause problems, God willing, but we won't allow anyone to interfere in Iraqi matters because this is a subject for Iraqis."
Still, while the resurgence of Najaf may have some impact on Iran, many analysts believe that it will not undermine the ruling clerics' grip on the country.
"I don't think [Sistani] is a threat to Iran's religious institutions," says Mohammed Hadi Semati, a Tehran University political scientist currently at the Carnegie Endowment for International Peace in Washington. "I don't think there will be a rivalry between Qom and Najaf ... though in the long-term, there could be rival doctrines [about clerical rule]."
Instead, any influence exerted by Iraq over Iran is more likely to stem from the successful introduction of a stable and democratic system of rule in Baghdad rather than from differences in Shiite theology.
"It's difficult to change the regime [in Iran]," says Professor Habib. "The Iranians stick to Islam more than Iraqis. The Iranian clerics have more influence over the people than the clerics in Iraq. But if the situation in Iraq develops and we succeed in democracy and prosperity, it will have a great influence on Iran. Iraq influences Iran, not the other way around."
• Scott Peterson contributed to this report from Tehran.