In a report presented to the US House of Representatives on Wednesday, Charles Duelfer, head of the Iraq Survey Group appointed by President George Bush to hunt for Iraqi WMDs, said Iraq had no stockpiles of biological and chemical weapons and its nuclear programme had decayed since the 1991 Gulf War.
The conclusions flew in the face of statements made by the US president before the invasion. Bush had cited a growing threat from Iraq's weapons of mass destruction as the reason for overthrowing former president Saddam Hussein.
Speaking earlier in the day in testimony prepared for the Senate Armed Services Committee on Wednesday, Duelfer said: "I still do not expect that militarily significant WMD stocks are cached in Iraq,"
He said Baghdad's nuclear weapons programme had deteriorated significantly since the 1991 Gulf War.
The issue has figured prominently in the campaign for the US presidential election, with Bush's Democratic opponent John Kerry saying Bush rushed to war without allowing UN inspections enough time to investigate Iraq's armaments.
Bush, who has given varying justifications for the war, said in a speech in Pennsylvania on Wednesday that the concern was that terrorists would get banned weapons from Saddam.
"There was a risk, a real risk, that Saddam Hussein would pass weapons or materials or information to terrorist networks," Bush said.
"In the world after September 11, that was a risk we could not afford to take," he said, referring to the 2001 attacks on the United States by al-Qaida.
Duelfer said a risk that has emerged since he last briefed the US congress on the status of the WMD hunt was a connection between chemical weapons experts from Saddam's former regime with fighters against the US-led forces now in Iraq.
Bush says the risk was that
Saddam could pass on WMDs
"I believe we got ahead of this problem through a series of raids throughout the spring and summer. I am convinced we successfully contained a problem before it matured into a major threat," Duelfer said.
"Nevertheless, it points to the problem that the dangerous expertise developed by the previous regime could be transferred to other hands," he added.
Duelfer said that by the time of the war in 2003, Iraq would have been able to produce mustard agent in months and nerve agent in less than a year.
"We have not come across explicit guidance from Saddam on this point, yet it was an inherent consequence of his decision to develop a domestic chemical production capacity," he said.
The top weapons inspector said that "despite Saddam's expressed desire to retain the knowledge of his nuclear team, and his attempts to retain some key parts of the programme (after 1991), during the course of the following 12 years Iraq's ability to produce a weapon decayed".
According to one official familiar with the report who spoke on condition of anonymity,
Saddam "was further away in 2003 than he was in 1991" from acquiring nuclear weapons.
Duelfer briefed the senate intelligence committee behind closed doors about his report in the morning and then testified before a senate armed services committee hearing.
"While it is clear that Saddam wanted a long-range missile, there was little work done on warheads. It is apparent that he drew the line at that point ... so long as sanctions remained," Duelfer said.
The US says Saddam was only
trying to escape UN sanctions
One of Saddam's priorities was to escape UN sanctions, he said.
"Over time, sanctions had steadily weakened to the point where Iraq, in 2000-2001 was confidently designing missiles around components that could only be obtained outside sanctions," Duelfer said.
Duelfer's key conclusion tallied with that of his predecessor, David Kay, who said when he resigned in January that no large stockpiles of biological and chemical weapons existed in Iraq when the US went to war.