It was only one line in a 531-page book, but US economic guru Alan Greenspan's comment that the Iraq war "is largely about oil" has provoked discussion - and a near retraction by the author himself.

In his book The Age of Turbulence: Adventures in a New World, Greenspan, 81, wrote: "I am saddened that it is politically inconvenient to acknowledge what everyone knows: the Iraq war is largely about oil."

For critics of US President George W Bush and the war in Iraq, the comment confirmed a widespread opinion that the US wanted to seize the oil reserves of the world's second largest supplier.

But Greenspan, who retired in 2006 as head of the US central bank, hastened to correct the impression in interviews published Monday by the Washington Post and the Wall Street Journal, saying the oil issue was his personal motive for backing the ouster of the late Iraqi leader Saddam Hussein, because it was necessary to secure the safety of world oil supplies.

"I wasn't arguing for war per se," Greenspan was quoted as saying in the Post. But "to take (Hussein) out, in my judgement, it was something important for the West to do and essential, but I never saw Plan B" - an alternative to war.

Greenspan told the Wall Street Journal that his main worry was that the Iraqi dictator wanted to control the Strait of Hormuz, the main passageway for a large portion of the world's oil supplies.

He said in the interviews that he expressed that view to the Bush administration in the build-up to the war, but he doubts oil played a major role in the final decision. He said when he brought it up, administration rejected the argument as one that would not fly politically.

US Defence Secretary Robert Gates Sunday said he disagreed with Greenspan's spin on the Iraq war.

"I know the same allegation was made about the Gulf War in 1991 and I just don't believe it's true," he told ABC news.

Gates said he thought the war in Iraq was "really about stability in the Gulf. It's about rogue regimes trying to develop weapons of mass destruction. It's about aggressive dictators." dpa da pr