To paraphrase Donald Rumsfeld, there were the known unknowns over the Iraqi weapons programme during the Saddam era, and the unknown unknowns.
The problem with trying to turn the remaining 'unknowns' into 'knowns' is that all the key figures from Saddam's regime are either in prison, in hiding or dead. But one key player has been tracked down by Newsnight.
Dr Jaffar Dhia Jaffar is described as the father of Iraq's nuclear weapons programme and was at the heart of the regime until Baghdad fell. Now debriefed by the CIA and MI6 he's given his first broadcast interview to Newsnight.
Our Security Correspondent Gordon Corera heard his version of events.
TONY BLAIR:
He has existing and active military plans for the use of chemical and biological weapons and that he is actively trying to acquire nuclear weapons capability.
PRESIDENT GEORGE W BUSH:
We cannot wait for the final proof, the smoking gun, it could come in the form of a mushroom cloud.
GORDON CORERA:
A face in the crowd on a busy Paris street. But this man holds the key to what happened inside Iraq's nuclear weapons programme.
DR JAFFAR DHIA JAFFAR:
There was no capability, there was no chemical or biological or any weapons of mass destruction.
GORDON CORERA:
Born in Iraq, but educated in Britain, Dr Jaffar Dhia Jaffar proved to be a brilliant nuclear scientist. He quickly moved into the higher echelons of the Iraqi government, working on its nascent nuclear energy programme. In 1980 his rise was temporarily halted when he was jailed for defending a colleague, whom Saddam had imprisoned. But in June 1981, when Israeli warplanes launched a surprise raid and destroyed Iraq's Osiris nuclear reactor, the man Saddam turned to, to rebuild the Iraqi programme was Dr Jaffar.
DR DAVID KAY
FORMER HEAD OF THE IRAQ SURVEY GROUP:
He was in many ways appropriately described as the father of Iraq nuclear programme. That is after the Israeli attack on the Osirak reactor in '81 when the Iraqis had to reconfigure their programme, it was Jaffar that came up with the means of enriching uranium, which they used as their primary means to get the programme started. He's very credible. He was well regarded by Saddam and his sons. So I view him a major figure.
GORDON CORERA:
We've been looking for Dr Jaffar since he left Iraq, just two days before the fall of Baghdad to coalition forces. He was granted a visa to enter Britain last November, but it was subsequently withdrawn. He is allowed into France. So we arranged to meet him here in Paris. So at what point did President Saddam Hussein ask you specifically to build a nuclear bomb for him?
DR JAFFAR DHIA JAFFAR
FORMER HEAD OF IRAQI NUCLEAR PROGRAMME:
In September of 1981, the day I came out of my incarceration I went to see him. At that time, the programme that we decided later was not to build the bomb, to develop an enrichment process.
GORDON CORERA:
But that could clearly be used as material for a bomb?
DR JAFFAR:
That eventually if it had succeeded could have been used to build a bomb. We went specifically we adopted a programme to build a bomb in late '87.
GORDON CORERA:
What did he say to you?
DR JAFFAR:
He... He told me we must develop a deterrent because if we had had a nuclear weapon, Israel wouldn't have bombed the Osiris reactor.
GORDON CORERA:
How close did you get to building a nuclear bomb before that first Gulf war in 1990?
DR JAFFAR:
I cannot say really how close because until you get there you don't know how close you are. It's difficult to estimate, but perhaps a few years.
GORDON CORERA:
After the 1991 Gulf War, UN inspectors like David Kay swarmed over the nuclear programme and found it far more advanced than they had expected. But according to Jaffar, for Saddam the new reality of intrusive inspections was just too much.
DR JAFFAR:
Facilities of the programme were damaged during the war. And Iraq did not have, would not have had the resources under sanctions to continue with the programme. And Saddam took a decision in July of 1991 to abandon the programme and destroy what remained of its equipment. He had orders to hand over the equipment to the Republican Guards, the Special Republican Guards. They had orders to destroy the equipment that we handed over to them.
GORDON CORERA:
So everything was destroyed?
DR JAFFAR:
Yes.
GORDON CORERA:
Everything?
DR JAFFAR:
Everything was destroyed, the programme couldn't be restarted at the time. And never restarted.
GORDON CORERA:
Never restarted at any points in the 1990s?
DR JAFFAR:
At any point.
GORDON CORERA:
There was never a request to do more research?
DR JAFFAR:
No, never a request for more research up to March 2003, up to the invasion.
GORDON CORERA:
How effective were sanctions and inspections in stopping a nuclear programme being restarted?
DR JAFFAR:
Well they were very effective. Saddam decided to terminate the programmes in July of 1991, hoping that the sanctions would be lifted soon because it was far more important to lift sanctions than to continue with these programmes. The strategic aim of these programmes became pretty much useless with the United States and Britain being involved as direct adversaries with Iraq. There was no sense in developing nuclear weapons programme against the United States. And that was why weapons of mass destruction, chemical weapons were not used in 1991 in the war of 1991. They were available.
GORDON CORERA:
He had them to use them?
DR JAFFAR:
They were available in the war of 1991.
GORDON CORERA:
Were they available in 2003?
DR JAFFAR:
No they were not available in 2003 because they had been destroyed and the programme was never reconstituted or reactivated. None of the programmes.
GORDON CORERA:
Including the chemical and biological programmes?
DR JAFFAR:
Of course.
GORDON CORERA:
You know that?
DR JAFFAR:
Of course I know that.
GORDON CORERA:
How do you know that?
DR JAFFAR:
Because I'm in touch with the people concerned.
GORDON CORERA:
And there was no development on those at any time after 1991?
DR JAFFAR:
No development after 1991.
GORDON CORERA:
What about the unaccounted for materials? There were 6,000 chemical war heads, there were supposed to be stock piles of sarin, VX, mustard? What happened to those? They were never accounted for by Iraq.
DR JAFFAR:
That's what the inspectors say. Iraq says they were accounted for. Books were not kept because nobody thought that inspectors would come years later and ask minute questions. At the time probably production was exaggerated because they would get benefit from a higher production. When you come to these reports later you find there's a difference between what was said was produced and what actually exists. That's what's called material unaccounted for, that doesn't mean it actually exists. It exists on paper perhaps, but it doesn't exist in practice.
GORDON CORERA:
How do you explain the Iraqi behaviour? You played cat-and-mouse with inspectors.
DR JAFFAR:
Who was the cat?
GORDON CORERA:
You weren't letting them in certain facilities...
DR JAFFAR:
Inspectors were the cat, we were the mouse.
GORDON CORERA:
By early 2003 and Colin Powell's presentation to the United Nations, the pressure on Iraq was growing. As war grew closer, politicians on both sides of the Atlantic made increasingly alarmist claims about Iraq's capability and inspectors argued that the past and present behaviour of Iraq and Jaffar himself, meant they must have something to hide.
DAVID KAY:
I think the failure to give Iraq a clean bill of health really relates to Jaffar's own behaviour that is they did not come forward with the evidence of their programme. We had to discover it. They lied, cheated and tried to deceive us. They tried to cover up and they tried to retain portions of that programme right up through '92. You can never be sure you'd gotten everything because the Iraqis failed to be honest about it. They started out lying. They continued lying. So consequently the attitude among inspectors developed, they never tell the truth. There must be more there.
GORDON CORERA:
What was your reaction in the run up to war, when you heard some of these claims coming from politicians about Iraq reconstitutuing its nuclear programme?
DR JAFFAR:
My reaction? I knew they were lying to their people. That was my reaction. And I knew they knew they were lying.
GORDON CORERA:
Why do you say that?
DR JAFFAR:
Well, the evidence for reconstituting a nuclear programme was presented in the British dossier. When I look at it, I was confident that they were lying because the evidence just wasn't there.
GORDON CORERA:
What about the claim that Iraq tried to procure uranium from Niger?
DR JAFFAR:
Why should we procure uranium from Niger? The documents were false.
GORDON CORERA:
But you had procured uranium from Niger in the 1980s.
DR JAFFAR:
Yes, and we had declared it to the IAEA.
GORDON CORERA:
So if you'd done it in the past, it's possible you were doing it again.
DR JAFFAR:
It's possible but we didn't, because we had 500 tons of yellow cake in Baghdad at the time, so why should we go and buy another 500 tons from Niger?
GORDON CORERA:
So you know that's categorically false you're saying.
DR JAFFAR:
Categorically false.
GORDON CORERA:
You know it to be false, it's not even possible?
DR JAFFAR:
It's not even possible. I know it's false.
GORDON CORERA:
How do you know that?
DR JAFFAR:
I know. I'm in the know. I know what goes on in atomic energy matters in Iraq.
GORDON CORERA:
Dr Jaffar remained loyal to the Iraqi regime until the very end, despite numerous offers to leave the country. As coalition troops made their way into Baghdad, he finally fled.
DR JAFFAR:
I planned my route through the north, into Syria. I was able to come out with my wife and daughter on the evening of April 7th.
GORDON CORERA:
Did any foreign governments help you out?
DR JAFFAR:
No.
GORDON CORERA:
Were you ever asked to defect?
DR JAFFAR:
Well, I was approached by intelligence agents.
GORDON CORERA:
Which country?
DR JAFFAR:
US.
GORDON CORERA:
And you were never tempted?
DR JAFFAR:
No.
GORDON CORERA:
Why not?
DR JAFFAR:
Because I don't think it's right to defect.
GORDON CORERA:
You tried to visit Britain in November 2003. What happened?
DR JAFFAR:
What happened to me was that they gave me a visa on a piece of paper and they asked me to go to the embassy the next day, they said there was something wrong with this visa, they had to correct it and when I went there they took the paper away and said we had instructions from the Foreign Office to refuse you the visa. And that was that. They never gave me my money back.
GORDON CORERA:
Have you any idea why they wouldn't want you coming to Britain?
DR JAFFAR:
I think they don't want me coming to Britain to give such an interview, perhaps. At the time it was sensitive.
Because the British Prime Minister, or perhaps others were still saying that Iraq had weapons of mass destruction yet to be found. But I think recently, even the Prime Minister has given that up.
GORDON CORERA:
If you'd succeeded in building a nuclear bomb for Saddam, would you have had no moral qualms about Hussein would repressed his own people?giving it to a leader such as Saddam
DR JAFFAR:
But we didn't get to that stage.
GORDON CORERA:
But you were on the way.
DR JAFFAR:
We were on the way, yes.
GORDON CORERA:
Did you not think about that?
DR JAFFAR:
Yes, I thought about that. But at the time I was very much engaged in the technical side and didn't really give these aspects much thought.
GORDON CORERA:
Why did you remain involved in the nuclear programme, especially when you knew Saddam was after a nuclear bomb?
DR JAFFAR:
Well, in my view it was important for Iraq to have a nuclear bomb as a deterrent. It was patriotic and all of my colleagues were of the same thought.
GORDON CORERA:
Because he managed to escape Iraq just ahead of coalition forces, Dr Jaffar is a free citizen, free to give his version of events from the heart of Saddam's regime. Whether he can escape his past is another matter.
This transcript was produced from the teletext subtitles that are generated live for Newsnight. It has been checked against the programme as broadcast, however Newsnight can accept no responsibility for any factual inaccuracies. We will be happy to correct serious errors.