The world has a new problem-solver. The summit of the Group of 20 in Pittsburgh last week confirmed that the leading economic powers, developed and developing, have cast their lot with collective economic leadership and systematic peer review. American conservatives are dyspeptic. The G20 seems to them both a fantasy in grand planning and a misguided sell-out of capitalist democracies to the miscreants of the third world. These fears are absurdly exaggerated but they do at least hint at an important truth: the G20 is an experiment. On its makeshift scaffolding the success of the planet now rests.

The G20’s true significance is not in the passing of a baton from the G7/G8 but from the G1, the US. Even during the 33 years of the G7 economic forum, the US called the important economic shots. Although the US constitutes only about 20 per cent of the world economy, it has until recently been the indispensable leader, the key to nearly every significant regional military alliance and to global trade, finance and cutting-edge technology.