But Tony Blair and President Bush cannot give this answer, as they asserted unambiguously that these weapons existed in justifying the war. So members of Blair’s Cabinet and Bush’s Administration have felt obliged to offer less plausible accounts of where the elusive weapons might be.

The most ambitious so far were put forward yesterday by Geoff Hoon, the Defence Secretary, in a fabulously implausible narrative which contradicated earlier statements by his Prime Minister, his colleagues and himself.

It is an understatement to say that the failure to find such weapons is an embarrassment for the British and American governments. Hans Blix, the chief United Nations weapons inspector, was always very careful to say that he was looking for weapons which were “unaccounted for”, discrepancies between what Iraq could have produced and what it had declared.

Blix never said they definitely existed. But Blair, Bush and their henchmen stepped repeatedly over that line, particularly in the frenetic and ultimately unsuccessful attempts to secure the backing of a second UN resolution.

In particular, Blair presented Parliament with a “dossier” on September 24 last year, headlined Iraq’s Weapons of Mass Destruction — The Assessment of the British Government. It said that “Intelligence has established beyond doubt . . . that Saddam has continued to produce chemical and biological weapons”.

The most dramatic claim of the dossier, much publicised, was that Saddam’s “military planning allows for some of the WMD (weapons of mass destruction) to be ready within 45 minutes of an order to use them”.

You do not have to be a fan of BBC Radio’s Today programme, or its breathlessly shrill style of interrogation, to concede that there is such a thing as a bad performance. Hoon delivered one yesterday in response to a shrewd series of questions, also the ones which any ordinary, interested person would ask first.

Top of that list is why the Saddam regime, facing annihilation, did not use weapons of mass destruction if it had them. According to Hoon, this is because the weapons were “scattered across Iraq (and) were well hidden” while UN inspectors were in the country.

But then they weren’t ready to use in 45 minutes, surely? Hoon appeared unaware of this claim. “I do not recall ever saying that. I specifically did not put a time on it,” he said.

No, he didn’t say it, but his Government did, and the claim is central to Britain’s justification for pressing ahead with the war. Hoon himself, just before the outbreak of war, made a speech that gave warning of the “very real threat today . . . of Iraq’s weapons of mass destruction”.

Hoon then alleges that the sudden onslaught of war disrupted command structures and prevented the weapons being reassembled. It didn’t seem that sudden at the time. Several days passed between the departure of the UN inspectors and the start of the bombing. There was also a solid two weeks after the bombing started in which Iraqi command structures looked anything but shattered, to the point where Washington was grimly bracing itself for a long war.

Why, on Hoon’s “well hidden” account, has nothing of significance been found, even though American forces have been in the country for more than a month? There is a limit to the number of possible hiding places. US Intelligence had identified about 150 sites worth investigation, and are already believed to have visited about half, according to analysts. Not one of these has yet yielded a “smoking gun”.

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