Retired Army Gen. David Petraeus agreed Monday with the overall Obama administration approach in Iraq stressing political unity while strongly disagreeing with Defense Secretary Ashton Carter’s charge that the Iraqis lacked the will to fight.

“During the surge and in the years after the surge, Iraqi forces fought and died for their country at vastly higher numbers than did U.S and coalition forces. We know that they can fight,” Petraeus said in an interview with the BBC.

Petraeus, who resigned as CIA Director, never mentioned Carter by name in the interview. Last month Carter said the Iraqi Security Forces (ISF) showed they lacked the will to fight in the fall of Ramadi.

“We know that they will fight,” Petraeus said of the Iraqis. “But they will only fight if they have good leadership, and the support and knowledge that somebody will have their back if they get into a tough fight.”

Petraeus, the former head of U.S. Central Command and U.S. and NATO forces in Afghanistan, echoed Carter and the White House in arguing for sectarian unity in the Baghdad government as the key component in the fight against ISIS.

“You cannot deal with an industrial-strength extremist problem just with force of arms,” he said. “You have to have that political component as well.”

Petraeus, who earlier this year pleaded guilty to a misdemeanor count for sharing classified material with his former mistress, took issue with the initial claims by the Pentagon and the White House that Ramadi’s fall should be seen in the overall context of ISIS being on the defensive.

Petraeus called Ramadi’s capture “a strategic loss in the sense that the narrative of ISIS being on the defensive — of losing — was shown to be somewhat hollow.” However, Petraeus added that “I do think Ramadi will be retaken in a matter of weeks or less.”

In Iraq Monday, ISIS suicide bombers, reportedly driving Humvees captured from the ISF, blew up the vehicles near a federal police headquarters in the town of Al Thartar north of Ramadi in Anbar province, killing at least 40.

On Saturday, Iraqi Prime Minister Haider al-Abadi said that the ISF lost about 2,300 Humvees last summer when ISIS fighters swept in from Syria to take the major city of Mosul and large swaths of territory in Anbar.

Abadi said on Iraqi state television that “we lost in the collapse of Mosul a lot of weapons and ammunition.”

“We cannot replace HMMWVs (Humvees) we lose in battles,” he said. “We lost 2,300 HMMWVs in Mosul alone. Besides, we are still losing HMMWVs because of the continuation of the fighting.

– Richard Sisk can be reached at Richard.Sisk@military.com