Some useful progress, but still a way to go. That must be the conclusion of the Group of 20 summit in London. Gordon Brown, UK prime minister and chairman of the meeting, set out a six-point plan to save the world. This reflected some real achievements: a generous increase in funding for the International Monetary Fund, a new issuance of special drawing rights and a boost for trade finance. He sounded disappointingly thin on other key areas – notably cleaning up banks and future fiscal stimulus. More detail would have been reassuring.

Mr Brown cast the G20 meeting as part of a co-ordinated “fight back against the global recession” and said the “global crisis requires a global solution”. We may doubt aspects of the solution, but the crisis is undeniable. World growth is expected to decline this year for the first time since the second world war. The World Trade Organisation expects that trade will fall by 9 per cent – a worrying prospect.

It has also become clear that this crisis will not simply burn itself out. Part of the genius of John Maynard Keynes was his explanation of how economies could be caught in low growth traps. The longer the recession, the greater the destruction of happiness. An extended downturn will also increase the risk of the crisis expanding and deepening far beyond its current spread. In new democracies, whether in Africa or central and eastern Europe, this is a moment of genuine peril. In some poorer countries, it could even lead to war and famine.