As a marketing tool, the Brics brand has been a huge success. It has focused attention on the rising power of five fast-growing economies that account for almost half the world’s population and a quarter of its economy. But for all its sunny show of unity, this week’s summit of leaders from Brazil, Russia, India, China and South Africa revealed there is still more that divides these powerful emerging markets than unites them.

Summit statements that condemn violence, call on the developed world to share power with developing countries and urge diplomatic dialogue with Iran are easy to agree. It is far harder to build common positions on issues such as security when there is deeply-rooted suspicion between Brics members themselves. Beijing and New Delhi are locked in long-standing border disputes, while Russia is stepping up its military investments to counter China’s. Trust is more difficult to build when political differences span the spectrum from communist to authoritarian to democratic.

It is also challenging to promote mutual prosperity when economies run on different fuels. The interests of a commodities exporter are quite different from an importer, for example.