I didn't make up what I am about to tell you. I promise you I didn't. I only provide you with this assurance because the comment I am about to report is so ridiculous, your first thought will be that I am having you on.

My first thought was different. It was that I could get a publishing deal for a book entitled 101 Shockingly Idiotic Comments. The only work now required is to find another 100 remarks that are anywhere near as idiotic.

On Saturday the results of an encounter between the journalist Allison Pearson and Gordon Brown were published. After a load of the usual stuff about eating cold lamb chops with his children and so forth, they finally get down to business. Pearson asks if the Prime Minister “if he has any regrets about his boast: ‘No more boom and bust'”.

And here is his priceless reply: “I actually said: ‘No more Tory boom and bust'.” Yes, that really was what he told her.

What is the best route to go down with this? One is the “how on earth does he think he can get away with such a barefaced lie” route. He repeatedly pledged that there would be no more boom and bust without mentioning the Tories. He did it all the time. And so did his mates.

The second route is the “excuse me while I fall about laughing” route. Mr Brown is the king of the cat ate my homework excuses but, even for him, this is risible. If he had said that he would do away with Tory boom and bust I think voters would have been entitled to conclude that he intended to do this by getting rid of boom and bust, rather than by retaining boom and bust and getting rid of the Tories.

I intend to go down the third route. Which is to take him seriously. Because I think that when you do that, the real truth of the events of the last month becomes clear. This has not been a triumph for Mr Brown, it has been a catastrophe. It is said that he is having a good war. I think this success is confined to the fluency of his signature on the surrender documents. He is having a good war, in the same way that the Kaiser had a good war. Some of his supporters argue that the last week has been his Falklands. True. And he is General Galtieri.

The serious argument that Mr Brown was trying to make is that the situation we are in is at variance with the economic cycles of the 1980s and early 1990s. In other words, that the boom and bust we are in is not the “old” boom and bust. So, strictly speaking, we are not “returning” to the boom and bust “of the past”. We have a new boom and bust.

The old boom and bust consisted of rapid fluctuations, with medium-sized boom followed by medium-sized bust. This time we have had a long period of growth, followed by a bust so bad that it has almost destroyed the financial system. And if we accept this idea, it means looking at the past decade anew.

For the past ten years the Government has been boasting of the stability it has brought to the economy, of the growth it has seen on its watch, of low interest rates and of the money it has been able to spend on public services. And this narrative has, generally, been accepted. Yet now this record appears very different.

In his book The Black Swan, the financial analyst Nassim Nicholas Taleb provides a useful analogy. In the months before Thanksgiving, turkeys begin to build up a theory about mankind. Man is benevolent. Every day he appears with more food, and the turkey is allowed to get fatter and fatter. And then, about a week before Thanksgiving, the turkey will, as Taleb puts it, “incur a reversion of belief”.

Our view of the Brown decade is like the turkey's view of mankind, utterly destroyed by what has now happened. The stability was a trick of the light, the lengthy period of growth was fuelled by house prices and debt, the low interest rates (of which Brown is still, amazingly, boasting) were an error. The length of the good years is being paid for by the severity of the crisis we now face.

As for the money spent on public services, Taleb has a story that is a useful analogy for that, too. He tells of his period working for the Bankers Trust and how every quarter they would boast of profits and of “how smart, profitable, conservative (and good looking) they were”. Then Taleb adds: “It was obvious that their profits were simply cash borrowed from destiny with some random payback time.”

And the same is true for the huge increase in spending on public services on which the Government embarked over the past ten years. Every quarter it boasted of how smart, profitable and conservative it was. But it was money borrowed against the future, on the assumption that a crash would never come. It was borrowed from destiny and the random payback time is now.

Gordon Brown is enjoying himself so much at the moment that it is sometimes hard to recall whether the aim of the exercise is for him to save the banks or vice versa. But to have to spend billions of pounds of taxpayers money to save the entire British banking system from collapse is an odd sort of triumph, I have to say. There appear to be some people who regard it as a victory that the Chancellor was sitting up until two in the morning hatching a desperate last-ditch plan to save the whole economy. But this description isn't one that flies to my lips.

There is room for plenty of argument about whether the crisis could have been averted by better management. But this is almost beside the point. What matters is not whether the bust was avoidable. It is that the preceding boom was illusory.

The idea that boom and bust had been abolished was not a small claim among many. It was the central claim of this Government. It was the boast of boasts - the boast upon which all other boasts were built. And now it has been revealed as totally empty. Not triumph, then. Disaster. Not victory. Total, utter, dreadful defeat.

daniel.finkelstein@thetimes.co.uk

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