Look for an organising characteristic in today’s world and speed is among the top contenders. Whether it is technology, financial markets, popular discontent or global geopolitical upheaval everything now runs at fast forward.

China’s progress to great power status has been in sight since the 1990s. But few western politicians or policymakers anticipated the breathtaking speed of its rise. At the opening of the present century China’s economy was about a quarter of the size of that of Japan. A decade on, China has overtaken its east Asian neighbour to occupy the world number two slot, remaking the international order along the way.

The coincidence of demographic change, rampant corruption, political repression and stifled economic opportunity in the Arab world was a fuse waiting for a match. Western diplomats insist without a blush that a popular explosion had long been among their policy assumptions. Let’s give them the benefit of the doubt. None predicted how quickly a flame lit in Tunisia would sweep across the Arab world.