After three years in this country, French journalist Jacques Monin has come to the conclusion that we are obsessed with money, drowning in debt and morally bankrupt. So where did it all go wrong?

If I had to choose a single image that, for me, represents Britain today, it would not be a phone box or a postbox. It wouldn't even be a double-decker bus. It would be a simple briefcase. A battered red one, the one the chancellor of the exchequer likes to brandish triumphantly in front of the television cameras when he leaves his residence at Number 11, Downing Street every budget day. It sums up, all by itself, the way this country now thinks.

The key words, the only words that really matter in Britain, are money, business, interest rates, profit, consumer spending, "good for the economy". I still do not understand why it is impossible, in this country, to talk about someone without mentioning their salary, the cost of their car, the value of their house. Even if you're talking about health, about a humanitarian act, it's in the context of cost. You have forgotten, it seems to me, that what matters is who you are and what you do. Not how much you cost.

In Britain, now, it seems all political thought works this way. In the battle against global warming, Gordon Brown professes to see an opportunity to save the world. But really it's about developing new business opportunities. Money is the answer to everything: it is used to reward smokers who successfully give up, and to resocialise the most hardened criminals by paying them, in prison, to re-engage with a semblance of a social life.

Earning lots of money is A Good Thing because - unlike the way we French see things - the search for profit does not rule out generosity. "Spend money and you'll be doing good" might, in fact, be a motto for modern-day Britain. Thanks to your fine charities (which, on the whole, do work that is done by the state in France ), you have managed to reconcile the social and the commercial. Look: by doing business and making money, you are contributing to the happiness of others! If morality very rarely intrudes on the business of making money, making money somehow becomes a moral act.

For some years now, it has been de rigueur for a certain elite in my country - and, of course, yours - to see in the British model the salvation of France, and to portray France as a kind of 1970s Britain: in genteel decline, needing a good dose of Thatcherism. Right now, we're not quite so sure. Oddly, you see, France still values prudence in economic management. Whereas here, the constant encouragement to borrow a lot and spend even more has caused the whole machine to crash, steaming, into the mire. Borrow as much as you can afford, folks, then (why not?) a little more, and spend, spend, spend! That was New Labour's magic recipe. The more generous the prime minister's praise of the City bankers, the more eager they were to dream up more and more sophisticated products. The resulting toxic assets now easily stand comparison with the worst of America's sub-prime problems.

Your government, meanwhile, is now up to its neck in debt, and you personally have probably borrowed too much, too. Household debt in Britain now stands at a barely imaginable 173% of gross disposable income, against 72% in France. Add all your debts together, in fact, and Britain is now further in the red than any other developed nation. It was excessive borrowing that forced up British property prices to such an insane extent, creating a bubble that has now well and truly burst. Credit, the hard drug pushed with such alacrity by the financial services industry, has finally succeeded in bringing the world to its knees: the banks are as good as belly-up, and individuals can no longer carry on spending with impunity. Inevitably, the job losses are mounting.

The British model, presented to us all as exemplary, simply could not last. It carried within it the seeds of its crisis. And because you became so addicted to the credit drug, because you lost all idea of what constituted responsible or sensible behaviour, Britain will now fall further and harder than any other major European nation. Inexplicably, you threw caution to the winds. Reason was sacrificed on the temple of economic growth, at all costs. When I objected to my English friends that this mad cycle of borrowing and spending would have to be paid for one day, they told me I was a pessimist. When, as recently as last September, I decided on the title of my book, they thought I was being needlessly provocative. Well, we've all seen what happened. Is it possible that money makes you blind?

So now, all of a sudden, the government - having closed its eyes to the City's depravities as long as it was generating that all-important growth - is now pointing a finger at the bankers and their bonuses, and denouncing "casino capitalism". Those who lit the fire, in other words, have the nerve to portray themselves as the firefighters. And to cap it all, while he's putting himself about as the saviour of Europe, Brown is unwittingly copying his French neighbours. Today, he's all in favour of greater state involvement in the economy. Today, he's happy to run up public debt, promise employment incentives and state support to sectors in difficulty. The man who gave the Bank of England its independence now urges greater regulation. He's even meeting the unions.

During his state visit to Westminster in March 2008, Nicolas Sarkozy, plainly dazzled by what he saw as Britain's prowess, frankly told your MPs: "We must take inspiration from what you have achieved in these last 20 years." Would he say the same today?

Britain has good reason to worry. You may (depending on which statistics you believe) have dealt with mass unemployment, but you ditched protection for British workers in the process. You've invested enormous sums in public services in recent years, but for any French person the efficiency of your health and education systems, your energy and transport networks, leaves much to be desired. The French may believe their model is failing; the crisis, debt, unemployment weigh heavily on them. But French benefits, French paid holidays, French pensions provide real, heavy-duty protection. How on earth will you manage here, with your staggering levels of public and private debt? Where will you find the resources to modernise? What, in heaven's name, are all the unemployed people to live on?

Curiously, none of this seems to have done a great deal to change Britain's political apathy. You no longer imagine, it seems to me, that there might actually be such a thing as a "choice of society". Along with New Labour, the very idea of anything resembling an ideology vanished. In France, on the other hand, politics still condition the life of the individual. Rightly or wrongly, my fellow countrymen still want to believe that a choice of society really remains possible. They might resist reform, as you like to point out, but they involve themselves - deeply - in politics.

Here, however, the boundaries between the major parties have been all but eroded. This drift to the centre, combined with the weakness of the extremes, has anaesthetised British politics. So the British don't vote very much. They don't object very much. They don't dream very much. The human has been replaced by the consumer. And humanism by pragmatism. Pragmatism, in today's Britain, is all. Cost-efficiency is what counts. Here, you're actively encouraged to denounce your neighbour, for not paying road tax or putting a bin out early or dishonestly claiming a benefit. Closed-circuit TV surveillance is rife. There are councils that spy on their taxpayers as if they were common criminals; others that submit benefit claimants to a lie-detector test. And while it's capable of mislaying the personal data of millions of its constituents, the home office proposes to set up a database holding information on every telephone call made, every email sent, and every website visited by every single British citizen. None of this would be possible in France; there would be rioting in the streets.

Let's be clear: the British and the French hold dear the same values of tolerance and fraternity. We distinguish ourselves by the way we behave, by our sensitivities, by our relations with the world. But the British model is, I'd argue, displaying its limitations. You have sacrificed everything to economic growth, but that has weakened the worse-off. It has done nothing to even out Britain's inequalities (indeed, it has exaggerated them). Your pensions are still a sad joke. Your public services are still not what they should be. Despite the all-consuming focus on efficiency, waste and incompetence continue to dog both the public and the private sectors (think the NHS computer debacle; think Heathrow's Terminal Five).

The current crisis, it seems to me, is more than economic. Britain is in a crisis of morality, and of identity. It is unsure, in the wake of 7/7, of its multicultural model; immigration is now a source of concern. Whole groups of young people are losing their bearings, becoming cut off from society, joining gangs, turning to knives. You have a growing obesity problem. Alcoholism is gaining a grip on the middle classes. In France, by contrast, young people generally feel stronger family ties, there is a greater respect for gastronomic traditions and while drinking levels may have increased, a bingeing culture has not yet taken hold. Britain faces big questions. Who are you in a globalised world, in a country with a population so diverse it is no longer sure of its roots? How do your traditions accommodate modernity, monarchy, a republic, discipline, eccentricity, tolerance, violence, extreme wealth, great poverty? What is man's place in a world where money and the media show are all that matter? What, in short, are your values now?

Faced with questions of such complexity, your celebrated British pragmatism is not, I fear, enough. I once shared my doubts with a British academic. "In France," he said to me, "you start from a principle, and you look at how best to apply it. In England, we work from the bottom up. We start from the facts, and we take a decision that will solve the problem. It's an approach that allows us to be simpler. And more efficient."

And perhaps, I believe after nearly three years in your magnificent country, to arrive at a rather simplistic vision of the complexity of man and of his aspirations.

• Jacques Monin is the London correspondent of Radio France. His book, Le naufrage britannique (The Shipwreck of Britain), is published by La Table Ronde, Paris