The post-invasion planning for Iraq was handled, in my opinion, in this alternative decision-making process which, in this case, constituted the vice-president and the secretary of defence and certain people in the defence department who did the "post invasion planning", which was as inept and incompetent as perhaps any planning anyone has ever done.

It consisted of largely sending Jay Garner and his organisation to sit in Kuwait until the military forces had moved into Baghdad, and then going to Baghdad and other places in Iraq with no other purpose than to deliver a little humanitarian assistance, perhaps deal with some oil-field fires, put Ahmed Chalabi or some other similar Iraqi in charge and leave.

This was not only inept and incompetent, it was day-dreaming of the most unfortunate type and ever since that failed we've been in a pick-up game - a pick-up game that's cost us over 2,000 American KIAs [killed in action]and almost a division's worth of casualties.

Now you call this alternative decision-making as a process and you seem to be laying the blame pretty fairly and squarely at the door of Dick Cheney. Am I correct in assuming that?

Well in the two decision-making processes into which I had the most insight - the detainee abuse issue and this issue of post-invasion planning for Iraq - I lay the blame squarely at his feet.

I look at the relationship between Mr Cheney and Mr Rumsfeld as being one that produced these two failures in particular and I see that the president is not holding either of them accountable, or at least up to this point he is not, and so I have to lay some blame at his feet too.

But you're talking about the abuse - the alleged abuse - by American forces aren't you?

I am, and I concluded that we had had an impassioned debate in the statutory process. And in that debate, two sides had participated: one that essentially wanted to do away with all restrictions and the other which said no, Geneva should prevail and the president walked right down the middle.

He made a decision that Geneva would in fact govern all but al-Qaeda and al-Qaeda look-alike detainees. Any other prisoners of course would be governed by traditional methods, international law, Geneva and so forth.

Who was calling for doing away with all the normal practices if you like?

Who is right now very publicly lobbying the congress of the United States, advocating the use of terror? The vice-president of the United States.

There was a presidential memo ordering that detainees be treated in a manner consistent with the Geneva Conventions that forbid torture. Are you saying that Dick Cheney ordered that to be ignored?

Well my critics have said that the president's continuing phrase in what you just quoted, "consistent with military necessity", was an out, under which almost anything could be done.

If I'm a soldier in the field - I'm an NCO [non-commissioned officer ] or I'm a private or a corporal - and I need to shoot even a detainee who might be threatening to kill one of my buddies or even me then I can do that.

It does not mean that I can go into a darkened cell with a detainee shackled with his hands above his head to the wall and beat him so that eventually he dies, and the army coroner declares it homicide, and two years later when the army quits obfuscating and throwing obstacles in the way of the investigations, people are actually punished for having murdered two individuals in Bagram, Afghanistan in December 2002.

And there were more than 70 such deaths - questionable deaths - of detainees under US supervision when I left the state department and I have people who are now telling me that the death toll was up to around 90.

And that question of detainee abuse - are you saying that the implicit message allowing it to happen was sanctioned by Dick Cheney - it came from his office?

Well you see two sides of this debate in the statutory process. You see the side represented by Colin Powell, Will Taft, all arguing for Geneva.

You see the other side represented by Yoo, John Yoo from the Department of Justice, Alberto Gonzales - you see the other side being argued by them and you see the president compromising.

Then you see the secretary of defence moving out in his own memorandum to act as if the side that declared everything open, free and anything goes, actually being what's implemented.

And so what I'm saying is, under the vice-president's protection, the secretary of defence moved out to do what they wanted to do in the first place even though the president had made a decision that was clearly a compromise.

It is quite difficult to believe though that Colin Powell wasn't aware of what was going on - if this alternative decision-making process was happening as you say - why didn't he do something?

Well you don't know that it's happening.

If what you say is correct, in your view, is Dick Cheney then guilty of a war crime?

Well, that's an interesting question - it was certainly a domestic crime to advocate terror and I would suspect that it is - for whatever it's worth - an international crime as well.

You've got also John Kerry recently accusing President Bush of orchestrating one of the great acts of deception in American history, and saying that flawed intelligence was manipulated to fit a political agenda. Now Colin Powell would be tarred with that same brush wouldn't he? Did he feel that he had correct information about Iraq's alleged weapons of mass destruction when he outlined the case against Saddam?

He certainly did and so did I. I was intimately involved in that process and to this point I have more or less defended the administration.

I have basically been supportive of the administration's point that it was simply fooled - that the intelligence community, including the UK, Germany, France, Jordan - other countries that confirmed what we had in our intelligence package, yet we were all just fooled.

Lately, I'm growing increasingly concerned because two things have just happened here that really make me wonder.

And the one is the questioning of Sheikh al-Libby where his confessions were obtained through interrogation techniques other than those authorised by Geneva.

It led Colin Powell to say at the UN on 5 February 2003 that there were some pretty substantive contacts between al-Qaeda and Baghdad. And we now know that al-Libby's forced confession has been recanted and we know - we're pretty sure that it was invalid.

But more important than that, we know that there was a defence intelligence agency dissent on that testimony even before Colin Powell made his presentation. We never heard about that.