It's happened twice this year. Sceptics about the war against Iraq find themselves shouting at the TV, overwhelmed with the urge to hammer their fists against the chest of a cabinet minister or wondering if they have woken up in an Alice-in-Wonderland country where black is white and white is black.
In mid-winter it was Hutton. In mid-summer it is Butler. The problem then was a Hutton report that seemed blind to the reality the rest of us had seen with our own eyes. The problem now is not the Butler report, which sees the reality clearly enough, but the government response to it. It's as if Tony Blair and friends live on a different planet, where the usual rules of reason and logic do not apply.
So cabinet minister John Reid can go on the Today programme and say - not once but twice - that caveats had to be stripped out of the September 2002 dossier in order to preserve the anonymity of intelligence sources. As if a "probably" here or a "maybe" there would have exposed our secret agents. Of course, it would have done no such thing. But Reid says it all the same.
We have the prime minister insisting that his own good faith cannot be questioned. Most politicians and commentators bow to this demand, too courteous to resist it. But it is a strange kind of good faith that enables someone to read intelligence on Iraq's weapons capability chock full of doubts and qualifiers - and then declare that this same intelligence establishes "beyond doubt" the nature of the Saddam threat. The one thing the intelligence did not do was establish anything beyond doubt - and Blair knows it because he read the doubt-filled assessments in their pre-cleaned-up form. Yet he said it anyway. We cannot ask why because Brutus is an honourable man.
Above all, we hear a former cabinet secretary lay bear a series of failings - in intelligence gathering, in public presentation, in top-level decision-making - which led, in part, to a major international disaster, a war costing many thousands of lives. And yet no one is blamed. Is there another sphere of human activity where this is imaginable? Let's say a public inquiry into a rail accident catalogued errors as copious as those identified by Butler: wouldn't the head of the train company be fired? If a football team had cocked up as badly as our intelligence services, wouldn't the manager be out on his ear? Yet politics is different. It turns out the buck does not stop with Blair or John Scarlett or Richard Dearlove or anybody. Ingovernment, it seems, there is no buck.
The anger and the sense of impotence this induces tend to be channelled towards the prime minister himself. Disenchanted voters decide they can't trust him; some even begin to hate him. This may be therapeutic but it's probably too easy. For what the Iraq debacle has shown is what Whitehall types would probably call systemic failure. It's not just one man who's at fault; the entire system is broken.
First confirmation of that came a year ago, when more than a million Britons took to the streets to oppose the war. Of course, governments should not bend to every public whim. But when close to a majority of the country reaches a settled will on a matter of great import, that surely shouldn't be ignored. Yet the war went ahead anyway, endorsed by a large majority in the House of Commons. Whatever your views on the Iraq question, this surely amounted to a democratic failure: the system did not fully reflect the views of the people it is meant to represent.
The Butler report identifies another structural malfunction: the over-centralisation of power, with too much authority concentrated in the person of the prime minister. So we have joint intelligence committee chairman Scarlett's obeisance to the prime minister and his aides manifested in his willingness to allow the caveat cull that changed so drastically the meaning of the dossier he was meant to "own". Out they came, Scarlett reassuring himself that these were purely presentational changes. Butler lays bare his dim view of this arrangement, even if he is congenitally unable to describe it so baldly.
The same point emerges in the account of the attorney general's efforts to determine whether an invasion of Iraq would be legal. He too ultimately deferred to Blair, seeking in March 2003 Downing Street's view of whether Iraq was in "material breach" of its UN obligations. On this question turned the legality of the war. Yet it was not determined by the attorney general, but the prime minister.