Despite some troubling episodes over the past decade, at least two top advisers to President George W. Bush think Ahmad Chalabi could be the one to save Iraq.

Chalabi, 69, is also the one credited with giving the Bush administration tenuous justification for invading Iraq, delivering false intelligence that then-Iraqi President Saddam Hussein possessed weapons of mass destruction. He was later accused of spying on the U.S. for Iran.

But former Bush adviser Richard Perle says he's still friends with Chalabi and defends his actions leading up to the Iraq War.

"Chalabi is far and away the most competent and the most capable of salvaging this situation," said Perle, who chaired the Defense Policy Board Advisory Committee from 2001 to 2003. "I think he's got the best chance. It would be foolish if we expressed a preference for somebody less competent, which we've done before."

Since his falling-out with the U.S. government, Chalabi has served in Iraq's Parliament and was named last week as a candidate to succeed Nuri Kamal al-Maliki as the country's prime minister. Pressure is mounting in Washington and Iraq for Maliki to resign because his Shia government has not welcomed the two other prominent Islamic factions, the Sunnis and Kurds, as the U.S. and Iraq had hoped it would. A unified government is seen as the first step toward preventing the insurgent group ISIS—the Islamic State in Iraq and Syria—from winning control over the region.

But a Chalabi rule in Iraq could be problematic for the U.S. Both the Pentagon and the CIA distanced themselves from Chalabi in the years following the invasion of Iraq. Republican Sen. John McCain, arguably Chalabi's biggest proponent in Congress leading up to the Iraq War and who once called him "a patriot who has the best interests of his country at heart," said Monday that the politician is "playing both sides" to get ahead.

"I am not a supporter of Mr. Chalabi," McCain said. "Since Chalabi started having close relations with the Iranians I have not supported him. From what I've heard, there's very strong opposition to him amongst the Iraqis."

Perle offered a different assessment of Chalabi's reputation among the Iraqis.

"I think he's under no illusions about whether the U.S. will support him, because of the long history of bureaucratic institutions not liking him," Perle said. "Whether people like him or not, they know that he is first and foremost an Iraqi nationalist that will put Iraq's interests first. Whereas Maliki put the interests of the Shia first."

Perle cited Chalabi's experience as head of the Iraqi National Congress—a Hussein opposition party established with the aid of the U.S. after the Gulf War to depose the Iraqi president—as evidence of Chalabi's ability to unite the Islamic factions in Iraq.

"Nobody would be talking about him now if he wasn't good at it," Perle said. "If the U.S. is smart, they will work with whoever is able to bring some order out of this chaos. The U.S. is in no position to declare that it doesn't like X or Y. They liked Maliki. It's time for a little humility from U.S. officials. We should not be picking Iraqi officials for the Iraqi people. It's time to let them do that themselves."

Another top Bush aide, Paul Wolfowitz, told Bloomberg News over the weekend that Chalabi would be a viable option.

"The man is a survivor," said Wolfowitz, who served as deputy Defense secretary from 2001 to 2005. "That's impressive. I think he wants to succeed in what he does, he's smart; maybe he'll figure out a way to do it."

Like McCain, Wolfowitz said he thought Chalabi's ties to Iran are a reason to be concerned.

"We've put him in a situation where, in my view, he's much too close to Iran," Wolfowitz said.

However Wolfowitz doesn't think that's a reason to prevent a future working relationship with Chalabi.

"Chalabi is not an angel; no one in that system is an angel," Wolfowitz said. "You have to be careful who you work with, but I think you need to try to work with everybody."