Yet one year later, neither weapons of mass destruction have been located nor have banned weapons programmes been recovered.
The following is a brief guide to who said what regarding Iraq's alleged WMD, before, during and after the war on Iraq.
10 April 2002, House of Commons, British Prime Minister Tony Blair: "Saddam Hussein's regime is despicable, he is developing weapons of mass destruction, and we cannot leave him doing so unchecked ... he is a threat to his own people and to the region and, if allowed to develop these weapons, a threat to us also."
26 August 2002, US Vice President Dick Cheney: "Simply stated, there is no doubt that Saddam Hussein now has weapons of mass destruction; there is no doubt that he is amassing them to use against our friends, against our allies, and against us."
24 September 2002, House of Commons, Blair: "It [the intelligence service] concludes that Iraq has chemical and biological weapons, that Saddam has continued to produce them, that he has existing and active military plans for the use of chemical and biological weapons, which could be activated within 45 minutes, including against his own Shia population; and that he is actively trying to acquire nuclear weapons capability..."
24 September 2002, Foreword to UK government assessment of Iraqi WMD, Blair: "What I believe the assessed intelligence has established beyond doubt is that Saddam has continued to produce chemical and biological weapons, that he continues in his efforts to develop nuclear weapons, and that he has been able to extend the range of his ballistic missile programme."
7 October 2002, US President George Bush: "America must not ignore the threat gathering against us. Facing clear evidence of peril, we cannot wait for the final proof - the smoking gun - that could come in the form of a mushroom cloud...the evidence indicates that Iraq is reconstituting its nuclear weapons programme.
"Saddam Hussein has held numerous meetings with Iraqi nuclear scientists, a group he calls his 'nuclear mujahidin' - his nuclear holy warriors. Satellite photographs reveal that Iraq is rebuilding facilities at sites that have been part of its nuclear programme in the past.
"Iraq has attempted to purchase high-strength aluminium tubes and other equipment needed for gas centrifuges, which are used to enrich uranium for nuclear weapons...if the Iraqi regime is able to produce, buy, or steal an amount of highly enriched uranium a little larger than a single softball, it could have a nuclear weapon in less than a year. And if we allow that to happen, a terrible line would be crossed."
29 January 2003, state of the union address, Bush: "Twelve years ago, Saddam Hussein faced the prospect of being the last casualty in a war he had started and lost. To spare himself, he agreed to disarm of all weapons of mass destruction. For the next 12 years, he systematically violated that agreement. He pursued chemical, biological and nuclear weapons even while inspectors were in his country..."
US President George Bush
7 February 2003, statement to UN, Bush: "The (Iraqi) regime has never accounted for a vast arsenal of deadly biological and chemical weapons."
25 February 2003, House of Commons, Blair: "The intelligence is clear: (Saddam) continues to believe his WMD programme is essential both for internal repression and for external aggression...the biological agents we believe Iraq can produce include anthrax, botulinum, toxin, aflatoxin and ricin. All eventually result in excruciatingly painful death."
11 March 2003, MTV debate, Blair: "If we don't act now, then we will go back to what has happened before and then of course the whole thing begins again and he carries on developing these weapons and these are dangerous weapons, particularly if they fall into the hands of terrorists who we know want to use these weapons if they can get them."
12 March 2003, US Defence Secretary Donald Rumsfeld: "He claims to have no chemical or biological weapons, yet we know he continues to hide biological and chemical weapons, moving them to different locations as often as every 12 to 24 hours, and placing them in residential neighbourhoods."
18 March 2003, House of Commons, Blair: "We are asked now seriously to accept that in the last few years - contrary to all history, contrary to all intelligence - Saddam decided unilaterally to destroy those weapons. I say that such a claim is palpably absurd."
10 April 2003, radio speech to the Iraqi people, Blair: "We did not want this war. But in refusing to give up his weapons of mass destruction, Saddam gave us no choice but to act."
4 June 2003, House of Commons, Blair: "There are literally thousands of sites. As I was told in Iraq, information is coming in the entire time, but it is only now that the Iraq survey group has been put together that a dedicated team of people, which includes former UN inspectors, scientists and experts, will be able to go in and do the job properly...as I have said throughout, I have no doubt that they will find the clearest possible evidence of Saddam's weapons of mass destruction."
8 July 2003, evidence to Commons liaison committee, Blair: "I don't concede it at all that the intelligence at the time was wrong....I have absolutely no doubt at all that we will find evidence of weapons of mass destruction programmes."
10 July 2003, report to US Senate armed services committee, Rumsfeld: "The coalition did not act in Iraq because we had discovered dramatic new evidence of Iraq's pursuit of weapons of mass destruction. We acted because we saw the evidence in a dramatic new light - through the prism of our experience on 9/11."
12 October 2003, BBC interview, chief US arms investigator in Iraq, David Kay: "We've found a strong body of evidence with regard to the intentions of Saddam Hussein to continue to attempt to acquire WMD... No one doubts that Iraq had weapons of mass destruction pre-1991. But 13 years of UN activity, including Dr Blix, was unable to confirm that the Iraqis had actually gotten rid of all those weapons as they claim."
16 December 2003, interview with British Forces Broadcasting Service, Blair: "The Iraq survey group has already found massive evidence of a huge system of clandestine laboratories, workings by scientists, plans to develop long-range ballistic missiles."
11 January 2004, interview with BBC Breakfast with Frost, Blair: "What you can say is that we received that intelligence about Saddam's programme and about his weapons that we acted on that, it's the case throughout the whole of the conflict .. And what I do know is that the group of people that are in there now, this Iraq survey group, they produced an interim report."
British Prime Minister Tony Blair
25 January 2004, US National Public Radio interview, Kay: "I don't think they [Iraqi WMD] exist... I actually think the intelligence community owes the president [an apology], rather than the president owing the American people."
25 January 2004, interview in the Observer newspaper, Blair: "I have absolutely no doubt in my mind that the intelligence was genuine... It is absurd to say in respect of any intelligence that it is infallible, but if you ask me what I believe, I believe the intelligence was correct, and I think in the end we will have an explanation."
28 Jan 2004, US Congress, David Kay: "We were almost all wrong" in assuming Iraq had illicit weapons.
6 February 2004, after launching inquiry into WMD intelligence to figure out why no weapons were found, Bush: "We're also determined to make sure that American intelligence is as accurate as possible for every challenge in the future."
8 February 2004, interview on American television, NBC's 'Meet the Press', Bush: "First of all, I expected to find the weapons. I based my decision on the best intelligence possible, intelligence that had been gathered over the years, intelligence that not only our analysts thought was valid but analysts from other countries thought was valid."