WASHINGTON - A FORMER Pentagon official who played a key role in planning the US-led war in Iraq has written a new book accusing former top diplomat Colin Powell, the CIA and other colleagues of botching the invasion and occupation of Iraq, The Washington Post reported on Sunday.

Douglas Feith, who served as under secretary of defence for policy until 2005, alleges that Powell as secretary of state 'downplayed' the degree and urgency of Iraq's threat but was never willing to openly oppose the invasion, the Post wrote.

Mr Feith castigates Mr Powell for failing to secure support from France and Germany for the war and to win Turkey's approval for US military movements on its territory, saying it amounted to a lack of effort and commitment, according to a copy of the manuscript obtained by the newspaper.

Mr Feith writes that Mr Powell could have taken a stand and argued with President Bush against overthrowing Saddam Hussein, and either persuaded the president or if not, resigned.

Known as a hawk allied with former defence secretary Donald Rumsfeld, Mr Feith says retired General Tommy Franks showed little interest in planning for the post-invasion occupation and accuses Condoleezza Rice, then national security adviser, as failing to coordinate policy on the war.

Mr Feith was the target of a probe last year by the Pentagon's inspector general which found that his office's intelligence reports before the war were 'inconsistent' with other intelligence agencies and found to be 'inappropriate' though not unlawful.

He defends his intelligence work, alleging the Central Intelligence Agency was producing shoddy reports and ignoring evidence of ties between Saddam and international terrorists.

The former Pentagon official says it was a mistake for President George W. Bush's administration to put so much emphasis on Saddam's alleged stockpiles of weapons of mass destruction, which never materialised.

He said secret intelligence reports about weapons programs were not needed to describe the threat posed by Saddam, given his past military adventures and repression.

The book also reveals that at a Dec 18, 2002 meeting of the National Security Council, President Bush said 'war is inevitable' - weeks before UN weapons inspectors were to issue their findings on Iraq and months before President Bush delivered an ultimatum to Baghdad, according to the Post.