So far the US-led coalition has found no firm evidence of banned weapons
A leading Western think tank, which helped set the agenda for the war against Iraq, has admitted to being surprised at the failure of US and British forces to find chemical weapons in Iraq.
The International Institute for Strategic Studies in London issued a report in September last year about Iraq's weapons of mass destruction, saying that Iraq probably had "a few hundred tons" of mustard gas, precursors for other agents and VX gas from earlier stocks.
It was the first major report on Iraqi capabilities and proved helpful to Washington and London as they made their own cases against Iraq in the following weeks.
Search 'not over'
At the launching of its annual Strategic Survey, Dr Gary Samore, one of the experts who wrote the Iraq report, accepted that neither chemical weapons nor the munitions to deliver them had been found, nor were likely to be found in large quantities, despite the predictions of the IISS and the British and US governments.
"The absence of chemical weapons was a big surprise," he said.
Dr Samore added, however, that the search was not over and might take some months.
And, he said, it had not been completely fruitless so far.
"They have found equipment and material which would have allowed Iraq to revive its programmes," he said.
He questioned why Saddam Hussein had not been more helpful to the weapons inspectors if he had nothing to hide.
"Was this the mother of all diplomatic blunders?" he asked.
IISS Director Dr John Chipman said that the institute was neither "nervous nor embarrassed" about its report.
Since international law exists outside the edicts of the UN, it should also be possible to garner legal and political legitimacy without direct UN involvement
IISS Director John Chipman
It had been at the cautious end of the predictions, he said.
In introducing the Strategic Survey, Dr Chipman did not use the weapons issue to justify the war against Iraq.
Instead, he said: "In the end, the most important legitimacy for the operation may well come most from a successful process of political reconstruction."
Such a shift is similar to one seen in American and British statements, which tend to concentrate now on the changes in Iraq rather than the removal of a threat from the country.
Role of UN
Dr Chipman had criticisms both of the US and some European countries, especially France, for their pre-war diplomacy.
The role of the UN in Iraq has caused continued controversy
"Overall, the Europeans were too interested in process to the exclusion of substance," he said.
"The Americans were concerned that... process would displace substance."
"What irked the French - and to a degree the Germans - was that the US was asking others to approve a decision it had already taken.
"What irked the Americans - and to a degree the British - was that French diplomacy seemed aimed at opposing American power per se."
He suggested that United Nations approval should not necessarily be sought for future conflicts (as it had not been for the war against Serbia in 1991).
"The UN has formally authorised very few wars. Since international law exists outside the edicts of the UN, it should also be possible to garner legal and political legitimacy without direct UN involvement."
Such a view will be welcome in London and Washington, but much less so in Paris or Berlin.
French Foreign Minister Dominique de Villepin himself gave a lecture only recently at the IISS which stressed the primacy of the UN.
On other issues the IISS said:
International terrorism: "It would be unwise, in view of the latest explosions in Saudi Arabia, to conclude that the audacity of the Iraq intervention had intimidated anti-American terrorists as well as rogue regimes."
US foreign policy: "A more open acknowledgement that the policy of pre-emption, allied primarily to the combat against terrorists as opposed to international rivalry in general, would do much to allay the fears generated by US statements."
Europe and Nato: "Unfortunately, Nato has lost its central position as the place at which Western states discuss their security perceptions."
The Middle East: "With the US electoral season beginning in earnest by the late autumn of this year, the window for diplomacy is narrow."
Asia: "The North Korean nuclear threat poses the greatest challenge but options are very limited."
India/Pakistan: "A final resolution of the Kashmir issue may not be likely, but India and Pakistan maybe able to reach agreement on measures to reduce fighting in the valley and lower the risk of war."