One of the most significant stories over the past two weeks of G20 frenzy got little of the attention it deserved. It was the news that most rich donor countries are continuing to renege on the promises to increase development aid they made the last time the UK hosted a big heads of government jamboree – the Group of Eight summit in Gleneagles, Scotland, in 2005.

Why so important? Because it shows the fundamental problem that the G20 has yet to prove it can overcome. Groupings that produce grandiloquent promises of international action are only worthwhile when they materially affect the domestic policy debates in their member countries. Breaking the G8 aid pledges has inflicted no significant political damage on anyone. (Italy is the worst laggard, and yet Silvio Berlusconi, one of the Gleneagles signatories, is back in power again in 2009.) In that regard, there is scant evidence yet that the G20 can perform any better than its widely discredited older cousin.