Baghdad, Iraq (CNN) — Iraqi troops left the strategically vital city of Ramadi — allowing it to fall to ISIS — because of a direct order from their military commanders of which Iraqi Prime Minister Haider al-Abadi was not aware, according to the powerful Sunni speaker of Iraq’s parliament.

Salim al-Jabouri, arguably the most powerful Sunni politician in the country, told CNN that Ramadi was abandoned last month because of “a clear decision to give the order to pull out — and after that Ramadi fell.”

Al-Jabouri added: “Even the Prime Minister — the general commander of the armed forces — was not aware of the orders to pull out. This led to big questions for us. Who has a direct interest in the army pulling out and not confronting ISIS?”

Asked who gave that order, he replied: “In command was the Golden Division, and after they withdrew, a collapse occurred, and ISIS controlled Ramadi.” He said it was unclear where the order to withdraw originated — whether the Golden Division was ordered to pull out by a higher command, or did so on its own. A parliamentary investigation is under way to establish these facts, he added.

“There are a number of answers that we need to confirm in a realistic form,” he said. “We fear that there are other hands involved in this that played a role in military decisions.”

The Iraqi army loss in Ramadi has been the subject of an international blame game in the media, during which U.S. Defense Secretary Ash Carter told CNN the Iraqis lacked the “will to fight.” Al-Abadi, the Iraqi Prime Minister, told the BBC that Carter had bad information, and the head of the Iranian Revolutionary Guards, Qassim Suleimani, said U.S. President Barack Obama had not done a “damn thing” to confront ISIS.

Al-Jabouri echoed assertions by U.S. officials that the Iraqi forces in the city were far from outnumbered by ISIS. “The number of ISIS fighters who entered Ramadi at the time of the fall was not large,” he said, “and I think morale played a huge role and it had an influence.”

Sectarian tensions are high over the fall of Ramadi, with some critics of the often pro-Shia Baghdad government suggesting it was reluctant to arm the Sunni tribes fighting ISIS there as it mistrusts them, but also reluctant to send adequate reinforcements to fight for a predominantly Sunni area.

Al-Jabouri said locals in Anbar province — like the Sunni tribes fighting there — should be the ones to liberate the province, but that previous campaigns in other towns against ISIS had left a bitter taste for some Sunnis. “The experiences in Salaheddin, in Tikrit and al-Dor sometimes play a discouraging role. There is concern that it would be repeated in Anbar, especially after the liberation operations in those areas. We have to be careful. We must not think only of the liberation of an area but also about what comes after liberation. How do we establish stability and security?”

Many will take that as a reference to the conduct of Shia fighting groups, whose human rights records are often questioned and whom some Sunnis fear.

In the 48 hours before the interview, al-Jabouri met the U.S. coordinator for the coalition against ISIS, Gen. John Allen, and he is expected to travel to Washington soon. He appealed for more aid from the U.S., and said that airstrikes could intensify along with — if the U.S. was willing — boots on the ground.

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