It was so predictable, even though almost nobody dared to predict it. After all the stories about rows, inflated expectations and threatened boycotts, the G20 summit ended up as a triumph — for the world economy, for financial markets and for Gordon Brown. Not only was there unanimous agreement and mutual congratulations among the assembled leaders — that is more or less inevitable at such occasions. Much more impressive, and surprising, was the range of issues the communiqué covered.

The agenda could be divided into four types of economic salvation: measures to save the collapsing world economy with fiscal and monetary stimulus; measures to save collapsing banks with government support; measures to save collapsing countries with help from international institutions; and measures to prevent another such collapse ever occurring again. In each of these areas the G20 could report substantial changes, although some of these may produce results very different from what some of the leaders appeared to expect.

Starting with the global economy, Gordon Brown was justified in describing the tax cuts, public spending plans and interest reductions already implemented by the G20 economies as the biggest economic stimulus of all time. While Mr Brown and Barack Obama would have liked an explicit promise from Europe to do even more if the recession deepens, the fact is that the US, British and Chinese economies are already starting to show signs of life in response to the dramatic measures taken since November.

Measures to support banks in America, Britain and continental Europe are also starting to yield results. But whereas these policies of financial support were described by the G20 leaders yesterday as enhancing “transparency” and removing toxic assets from the global banking system, they will actually do the opposite. The accounting changes will make it easier for banks to hold on to their troubled loans until the crisis is over and for governments to support their banking systems indirectly instead of asking parliaments for trillions of dollars, euros and pounds of taxpayer funds. While these changes may be condemned by dogmatic believers in free markets, they will help to stabilise the world economy.

The biggest surprise was the decision to support struggling developing countries with a package of new export credits and up to $750 billion of new money for the IMF. The increase was bigger than the $500 billion expected — and even more surprisingly, the G20 leaders agreed to a new allocation of Special Drawing Rights, a form of international money that can essentially be printed by the IMF. These announcements triggered an immediate rally in the currencies and bonds of all the troubling emerging markets, especially those of Eastern Europe. It remains to be seen whether conditions attached to IMF assistance will prove acceptable to the governments of Eastern Europe — or whether China and other countries gaining influence on IMF decisions will agree to help European countries on easier terms than those offered to Asian, African and Latin American countries in the past.

Finally there is global regulation. This is where Germany and France apparently achieved their greatest triumphs — imposing tighter regulations on investment banks and hedge funds, closing tax havens and “turning the page on the Anglo-Saxon financial model”, in the words of Nicolas Sarkozy. The details, however, suggest that Mr Sarkozy may have overestimated his triumph. The new rules will do nothing to make low-tax jurisdictions less attractive to businesses, as Germany and France had hoped. In fact, financial institutions will again become extremely profitable if the G20 agreement brings forward a global economic recovery. That is a prediction nobody may be bold enough to make at present.

Times Recommends

• Strip away the figleaf and reveal naysayers
• Dave’n’George: there may be trouble ahead
• I do not accept that £64,000 a year for politicians is peanuts