NAJAF (Iraq) — In the struggle to transform Iraq from a dictatorship to a democracy after the US-led invasion in 2003, Grand Ayatollah Ali al-Husseini al-Sistani, the highest spiritual authority for many of the world’s Shiite Muslims, stood out as a singular champion of the effort to hold direct elections and ensure that politicians, and not clerics, rule the country.

In doing so, he shaped the relationship between religion and politics here as distinctly different from the Shiite theocracy in Iran, where another ayatollah wields supreme power.

Now, in the face of concerns over the growing power of Iran and its militia proxies amid a sectarian war in Iraq, al-Sistani has made one of his biggest interventions in Iraqi politics, to try to strengthen the Iraqi state, experts say.

For more than two months he has issued instructions, through a representative during Friday sermons, to Prime Minister Haider al-Abadi to hold corrupt officials accountable, to reform the judiciary and to support the national security forces instead of Iran-backed militias. Al-Sistani’s son, meanwhile, has kept up direct phone communication to the prime minister’s office, pushing for quicker reforms.

This latest intervention has provoked a new round of questioning by political leaders and diplomats in Baghdad: As al-Sistani has stepped in, once again, in the name of helping a country plagued by crisis, is he actually creating a fundamental shift toward clerical rule?

“Many people are surprised, very surprised, when they see Sistani so involved in politics,” said a senior Shiite leader in Baghdad who spoke on the condition of anonymity because he did not want to be seen as critical of al-Sistani.

Referring to Iran’s supreme leader, Ayatollah Ali Khamenei, and its revolutionary leader, Ayatollah Ruhollah Khomeini, he said, “In reality, in practice, he is doing what Khamenei does, and what Khomeini did.”

Al-Sistani, 85, is frail, has often travelled to London for medical treatment, and is rarely seen in public. Still, he frequently greets visitors in his bare-bones office in a rented building in Najaf that is down a narrow alleyway not far from the Imam Ali Shrine, one of the holiest sites in Shiite Islam.

As the supreme Shiite spiritual leader — whose religious authority surpasses that of Iran’s supreme leader — he instructs the pious in how to pray, how to wash and what to eat. Through his website, he recently advocated the use of body armor by fighters battling the Islamic State, prohibited women from using cellphones to contact strange men, and advised that men should not have goatees.

Despite his undeniably powerful influence, his public role in Iraq has often been described as “fatherly”: guiding politics from on high, intervening at difficult times, but otherwise staying aloof from the fray of governing.

So far, though, al-Sistani’s push for reforms, while embraced by al-Abadi, has borne little fruit, underscoring the opposition among the prime minister’s rivals and the depths of corruption and dysfunction. Al-Abadi has reduced the salaries of lawmakers and the number of their bodyguards, and has eliminated several high-level positions, including deputy prime minister and vice president, but there has been no serious effort yet on corruption or reforming the judiciary.

Last year, al-Sistani issued a widely heeded call for young men to take up arms against the Islamic State. But that fatwa resulted in a constellation of new militias, and the growth of existing ones that are controlled by Iran rather than the Iraqi state.

The influence of Iran and its militias in Iraq has grown as they have become essential to the fight against the Islamic State, also known as ISIS or ISIL.

Al-Sistani has become increasingly concerned that those militias are a threat to the unity of Iraq, experts say, in part because many of the militia leaders and their affiliated politicians have challenged efforts by the government to reconcile with Iraq’s minority Sunnis, a priority for the clerical leader.

But even as he moves to diminish Iranian influence in Iraq, he is mimicking the ways of the Iranian system.

One diplomat in Baghdad, referring to the Shiite holy cities from where instructions to politicians are given at Friday sermons, noted that in much the same way as Iranian political leaders look to Qom for guidance, “Every Friday we look to Karbala and Najaf.”

Here in Najaf, where al-Sistani, three other senior ayatollahs and countless clerics collectively represent the Shiite religious establishment, known as the marjaiya, there is a sense of regret for lending crucial support for Iraq’s Shiite political class in the years after the 2003 invasion.

The marjaiya’s support over the years lent crucial legitimacy to the Shiite religious parties that came to dominate politics and that are now the source of great anger for the masses that began protesting against Iraq’s government in August.

“We are all suffering from the past,” said Naseer Kashif al-Gita, a cleric in Najaf. “We need to force the politicians to implement things. The role of the marjaiya is to be the protector of the rights of society.”

Yet, al-Sistani’s son, Muhhamed Ridha Ali, in a brief interview here, suggested that the intervention in politics is not designed to be permanent.

“Maybe after one year he will be silent,” he said. THE NEW YORK TIMES