Former US Secretary of State Colin Powell has secured his place in history, not as a great American military leader, national security advisor, or diplomatic representative of his country, but rather the dupe who peddled false intelligence data to the Security Council of the United Nations on that fateful day on 5 February 2003, sealing the US case for war with Iraq. Powell, once revered as an American hero, will be remembered as Bush's shill for a sham case for war, waxing eloquently: "What we're giving you are facts and conclusions based on solid intelligence" for ever fixed in the minds of the more than 150 million people who watched him that day.

Former US Secretary of State Colin Powell has secured his place in history, not as a great American military leader, national security advisor, or diplomatic representative of his country, but rather the dupe who peddled false intelligence data to the Security Council of the United Nations on that fateful day on 5 February 2003, sealing the US case for war with Iraq. Powell, once revered as an American hero, will be remembered as Bush's shill for a sham case for war, waxing eloquently: "What we're giving you are facts and conclusions based on solid intelligence" for ever fixed in the minds of the more than 150 million people who watched him that day.

Powell repeated his role this past week when, in an interview with the German magazine Stern, he reflected on his historical moment before the council: "The CIA believed there were weapons of mass destruction," Powell said. "The president believed it. I believed it. Still, it was wrong. I did not know this at the time." Ever the good soldier, Powell this past week performed another service in defence of this charade: pre-empting a damning report on the CIA's intelligence about Iraqi WMD which was released a day after Powell's interview. This report, a product of the Presidential Commission on Intelligence and WMD, is critical of what it calls the CIA's failure to accurately assess the true status of Iraq's weapons of mass destruction capabilities in the lead-up to the March 2003 US-led invasion of Iraq.

The Presidential Commission's report speaks of the "worthless or misleading" assessments produced by the CIA. Building on the foundation established by Colin Powell, the commission placed blame for this failure on the CIA, quashing any notion of political pressure influencing the assessments by emphasising that: "The analysts who worked on Iraqi weapons issues universally agreed that in no instance did political pressure cause them to skew or alter any of their analytical judgements". This is a curious statement, given the fact that the CIA's October 2002 National Intelligence Estimate on Iraq, used to justify the decision to go to war against Iraq, was published almost two months after President Bush made his decision to invade Iraq. The commission, in an understatement, did note: "It is hard to deny the conclusion that intelligence analysts worked in an environment that did not encourage scepticism about the conventional wisdom."

As the commission's own report shows, when it came to Iraq and its weapons of mass destruction programmes, the CIA had ceased to function as a professional intelligence agency, tasked with discerning fact, and instead had transformed itself into a clearing house of rumour and speculation. In this diseased environment, defector reports that under any other circumstance would have been discarded as fictitious were certified as viable and then used to germinate numerous other corroborating intelligence reports that were treated as separate accounts, and yet had as their genesis the same errant report. In the same way, intellectual "traps" were manufactured where a hypothesis which postulated Iraqi guilt were constructed, together with the notion that any information that was uncovered which contradicted this hypothesis was to be dismissed as being part of an elaborate Iraqi "cover story".

The Presidential Commission's report smooths over the role played by the British government in promulgating falsehoods about Iraq's WMD programmes. The September 2002 "dossier" on Iraqi WMD capabilities has already gone down in history as a totally discredited work. Like the just-released US WMD report, the British carried out their own charade of an investigation into its intelligence failures, known as the Butler Commission. The commission was averse to any notion that it was pressure from policy makers that produced the inaccurate analysis of Iraqi WMD, and as such its report cannot be seen as anything more that yet another whitewash, designed to shift blame for the Iraq WMD intelligence analysis debacle away from Prime Minister Blair and on to the shoulders of the British intelligence community.

In the end, it is the policymakers - British and American alike - who must shoulder the responsibility for the Iraqi WMD fiasco. This was very much an elective war, not a conflict of necessity. In their headlong rush to get rid of Saddam Hussein, George Bush and Tony Blair violated not only international law and the moral character of their own respective democratic constituencies, but also the intellectual integrity of the very intelligence services the citizens they are responsible for depend on to help guide them through a dangerous world.

The Presidential Commission says that the CIA was "dead wrong" when it came to assessing Iraqi WMD capabilities, but the fact of the matter is that it is George Bush and Tony Blair who were dead wrong, to the tune of over 1,500 American, nearly 90 British, and tens of thousands of Iraqi lives lost, in pursuing a war on such blatantly false premises.

The American people have already shown themselves to be culpable in legitimising this tragedy by re-electing George Bush, the chief architect of this disaster, as president of the United States. In the weeks to come, the citizens of Great Britain will have a chance to carve their names in the annals of history, either slavishly repeating the same mistake of their American cousins by re-electing a man who is responsible for a massive violation of international law, or establishing the viability of British democracy as a lasting bastion of the rule of law by voting out Tony Blair. This will send a clear and lasting signal to those on the Presidential Commission and the Butler Commission that illegal wars of aggression are the responsibility of the politicians who order them, not the intelligence officials who justify them.

Scott Ritter was UN chief weapons inspector in Iraq from 1991 to 1998 and is author of 'Iraq Confidential: The Untold Story of America's Intelligence Conspiracy', which is to be published in the summer by IB Tauris & Co