Today's Guardian poll of global gloom shows the British as the most pessimistic nation on earth. They have the lowest expectation of economic recovery and the lowest opinion of their government. On any level, they must be cheered up. Misery feeds on itself.

Last week's G20 summit proved to be Gordon Brown's Falklands moment. By means of kinetic diplomacy he turned disaster into brief triumph. He did so, like Margaret Thatcher during the Falklands war, by locking up the reporters in a watertight compartment - be it a cruiser or a Docklands shed - denying them contact with key players and force-feeding them good news. It worked. Brown got the best press of his life.

Commentators are now pointing out that the G20 was a policy failure for Brown. He and Barack Obama did not achieve a new global fiscal stimulus. They did not reopen world trade or truly close tax havens. The summit yielded no agreement on demand stimulus or on measures to cut unemployment. It yielded old-style G8 promises of more loans to poor countries through the IMF, which may never be used.

Yet this does not matter. What did matter was an agreement, even an agreement on nothing. Authority had to seem coherent. Cats had to pretend to be herded. Brown had to pretend a success, and journalists entombed in the Royal group of docks had to declare a triumph. At this stage in a recession any triumph is welcome. It shows "the sneer of cold command", the talisman of control. It reassured the pessimists by implying that something was being done.

A yawning gap is opening between pessimism and optimism over the state of the world economy. At G20 the pessimists were the British and Americans, and the optimists were most of the rest, led by the French and the Germans. The former believed that government had to be seen as doing something to stimulate economic activity or confidence would continue to collapse. The latter believed that the recession will end of its own accord and that enough has been done to expedite it. For the optimists, the real debate is how to stop another such collapse occurring - caused as it was by Britons and Americans.

This gap is becoming ideological. Pessimists hold that any modern economy needs corralling, channelling and chaining, or it will go berserk. They view the free-market motorway pile-up of last autumn as a total systems failure. In future, they say, all cars should go on rails, with signals and points dictating every turn. The cars should be driven only by civil servants.

The clearest warning against this route is by Vince Cable in his excellent book The Storm, out this week. It leads, he says, to "an emerging state capitalism" in which Chinese and Russian attitudes to industry and trade predominate. According to Cable, over-ruthless market regulation could become "a generalised movement towards dirigisme and state control of economic activity". That is precisely the statism that Callaghan attacked 30 years ago, in telling the Labour party that "we cannot spend our way out of recession". It was to become New Labour's motto under Tony Blair.

The pessimists have revived a dangerous expectation in the power of government to lead them out of recession. Public opinion seems eager for any intervention, however daft, if it promises only to rescue the economy. As a result, the Treasury has assigned about £200bn to banks without any control or test of value for money. It is inconceivable that such money would be given so freely anywhere other than to banks. The intention was to stimulate lending and thus maintain demand. The opposite has happened. The policy has failed and unemployment is soaring.

Optimists would pursue an opposite policy. They would certainly bring bankrupt banks under public control (as would Cable), temporarily, to secure depositors' money and loans. They would then put the banks' investment arms into administration, to ensure that no public money was used to underwrite bad debt.

They would print money but give it not to banks but to consumers, to maintain high-street demand - since without demand there is no one to whom the banks can lend even if they were so minded. Optimists would boost money supply intravenously, notably by giving to those with a low propensity to save. That might mean temporarily doubling pensions and social benefits, handing out time-limited spending vouchers, and making short-term cuts in VAT, excise and stamp duty.

In other words, optimists would put money in the hands of people to buy goods and services, and let the economy recover on the basis of that demand, not through dilatory bank lending or public works. The British are good spenders and demand will work in time. Within a couple of years Dr Johnson would be proved right, in saying of the South Sea Bubble that it would one day seem "little more than a panick terrour from which, when they recover, many will wonder why they were so frightened".

The gulf between pessimism and optimism reflects a continuing gap between socialism and individualism. Everyone now accepts the need for government to regulate markets. Equally, everyone accepts that markets must prosper for economies to recover. No one wants a return to a wholly statist economy. The search is on for a golden mean.

Yet in Britain, the pessimists have the best tunes. Even the Tories seem unable to snap out of a me-too approach to the credit crunch, approving each new bank bailout as if dancing on a Labour marionette. Their old monetarism, which would today advocate a liquidity surge, has been broken on the wheel of Thatcherite unpopularity. The Tories are back to Heathism and the public sector consensus.

The pessimists, Labour and Tories alike, harbour a conviction that citizens are not to be trusted with their own money or used as prime agents of recovery. They would rather governments or bankers spend the taxpayers' money on the public's behalf. The one silver lining on today's cloud is the glaring evidence that this paternalism does not work.

That is why Brown's failure at the G20 last week was good news. It put "global fiscal stimulus" back in the statist box and said to the citizens of the world: we have made a total mess of your economies and are leaving it to you to get out as best you can. Now those citizens have a chance.

simon.jenkins@theguardian.com