I keep stumbling across unswerving predictions that the future belongs to China. Or, perhaps to the contrary, that the Middle Kingdom will always struggle to challenge US primacy. Don’t ask where India and Brazil fit in. Enjoyable as it is, this exercise in the remaking of the geopolitical landscape is also something of a diversion. The 21st century will not be shaped by the abstract choices of states. Transformative power will belong to a new global middle class.

The story of the past couple of decades has been of the great shift of economic weight and geopolitical influence from west to east. This rebalancing still has some way to go. However, comparisons of the relative position of established and emerging powers obscure some of the more fundamental drivers of change. What is happening within states is every bit as interesting as what might change in the relationships between them. Within 20 years or so a world that is now predominantly poor will be mostly middle class.

States, of course, will remain the dominant form of political organisation. Increasing wealth is unlikely to displace cultural and national identities. In some cases, it may well reinforce them. Resurgent nationalism could prove to be one of the big threats to international peace and security. But the way most new global actors behave will be steered by an unprecedented redistribution of power from rulers to ruled.