Former Australian leader John Howard has said he was embarrassed that the US intelligence on weapons of mass destruction he used to send troops to Iraq in 2003 proved to be unfounded.
But he denied that the conflict which toppled Saddam Hussein's regime is the main reason for the emergence of Islamic State jihadists in Iraq and neighbouring Syria.
Howard, prime minister from 1996 to 2007, said at the time he decided to send Australian soldiers to Iraq with US and British forces it was in the belief that Iraq had WMD.
"I was struck by the force of the language in the American national intelligence assessment late in November 2002," he told the Seven Network in an interview late Sunday.
"It brought together all the American intelligence and paragraph after paragraph, they said, we judge Iraq has got weapons of mass destruction and even talked about potential nuclear capacity."
"Now that wasn't made up. It may have been an erroneous conclusion based on the available information but it wasn't made up."
No WMD were ever found in Iraq, undermining the basis for the conflict which left thousands of Iraqis and foreign soldiers dead.
"I felt embarrassed, I did. I couldn't believe it because I had genuinely believed it," Howard said.
"So, I felt embarrassed and I did my best to explain ... that it wasn't a deliberate deception."
Howard also said it was wrong to say that the Iraq conflict alone created the Islamic State group.
"So much of the Islamic State operation comes out of what is occurring in Syria and to suggest that it's purely or predominately a result of what happened in Iraq in 2003 is a false reading of history," he said.
But lawmaker Andrew Wilkie, a former intelligence officer, accused Howard of rewriting history, saying Australia's own intelligence organisations had provided secret briefings to him which had explained US and British motives for war.
Australia's intelligence had also cast doubt on whether Baghdad had WMD, he said, making instead a compelling case that it had a disjointed and contained WMD programme which was not a threat to the region, let alone Australia.
"It's not good enough for John Howard to cherry-pick one particular report and to hold that up as the evidence to use for him to rewrite history," Wilkie told reporters Monday.
He said there was no doubt the Islamic State group had emerged from the war.
"If we had not gone to war 11-and-a-half years ago... then the circumstances would not exist for IS to have emerged and grown strong," he said.