Over the past three years, conventional wisdom divided the world’s major economies into two basic groups – the Brics and the sicks. The US and the EU were sick – struggling with high unemployment, low growth and frightening debts. By contrast the Brics (Brazil, Russia, India, China and, by some reckonings, South Africa) were much more dynamic. Investors, businessmen and western politicians made regular pilgrimages there, to gaze at the future.

But now something odd is happening. The Brics are in trouble. The nature of the problem in each nation is different. But there are also some broad difficulties that link them. First, for all the hopeful talk of “decoupling”, the Brics are all affected by weak western economies. Second, all five nations are finding that endemic corruption is eroding faith in their political systems, and imposing a tax on their economies.

China remains the daddy of the rising powers. It is the second-largest economy in the world – and easily still the fastest growing Bric. And yet the country feels more uncertain about its economic and political future than in many years. As a Chinese friend put it recently: “Our economy is slowing sharply, our next leader has disappeared, and we are sending ships towards Japan.” Xi Jinping has since reappeared – as mysteriously as he disappeared in the first place. But political tensions remain high, with the trial of Bo Xilai about to start and a crucial party congress approaching.