When the US wanted a Shia cleric to strengthen the credibility of the IGC, it turned to Bahr al-Ulum, whose family had lost many members for opposing Saddam Hussein.
But watching his hometown of Najaf come under US bombardment to crush Muqtada al-Sadr and his supporters, Bahr al-Ulum has lost faith in US intentions towards Iraq, and says millions of moderates like him, who welcomed last year's invasion, now regard Washington as an enemy.
"The Americans have turned the holy city into a ghost town. They are now seen as full of hatred against Najaf and the Shia. Nothing I know of will change this," the former president of the now defunct council said on Friday.
"I do not understand why America craves crisis. A peaceful solution to the confrontation with Muqtada could have been reached. We were hoping that Prime Minister Iyad Allawi would lead the way, but he sided with oppression."
Bahr al-Ulum has been one of the most outspoken critics of violence fuelled by al-Sadr and his supporters, who have challenged the authority of elder clerics such as Ayatollah Ali al-Sistani and Bahr al-Ulum himself.
Bahr al-Ulum says al-Sadr (R)
should have been given a voice
The established clerical class has come under mounting criticism from ordinary Shia for remaining silent over the US offensive, especially al-Sistani, who expressed sorrow at the events in Najaf, but did not condemn the US offensive.
Al-Sistani travelled to London as US forces launched their offensive on Najaf last week, to seek treatment for a heart condition. His aides say the problem is not life-threatening.
Al-Sadr's supporters see Iranian-born and Iranian passport holder al-Sistani as a foreign cleric who staffed the Najaf seminaries with his followers at the expense of Iraqi nationalist clerics.
Al-Sadr's father, Ayatollah Muhammad Sadiq al-Sadr, challenged al-Sistani's authority as well as that of Saddam. He was killed in 1999. Iranians and Iraqis exchanged accusations blaming each other for the killing.
Bahr al-Ulum, who acknowledges al-Sistani as the supreme living Shia religious figure, suggested that he would have condemned the US offensive if he had full knowledge of it.
"Sayyid (Shia title) al-Sistani is ill. I do not think he has knowledge of the destruction being wreaked in Najaf. He might have a vague idea of clashes, but not killings and oppression," he said.
It remains to be seen whether the US offensive on Najaf will undermine al-Sistani in the long term, and how much influence he will retain among Iraq's Shia.
Plight of the poor
Like his father, al-Sadr made the theme of dispossession a basis for his political platform and raised the plight of the poor, saying living conditions have not improved since the US toppled Saddam.
Although the young al-Sadr lacked political maturity, dealing with him through force only bolstered his support especially among the poor and unemployed, Bahr al-Ulum said.
"The government has lost the support of the Middle Euphrates region and the south, even if it manages to calm down these areas temporarily using brute force," he said, referring to clashes in central and southern Iraq.
He said al-Sadr should have been given a political voice in government to avert violent confrontation. "There is no wisdom to what the Americans and Allawi are doing," he said.
"The consequences are unthinkable."