Since the dawn of civilisation, kings, emperors and other men and women of wealth have wanted to rule the world, but none has succeeded. Every empire that arose on the blood of the people it subjected and enslaved – the ancient kingdoms of Egypt and Assyria, the successive Persian and Chinese empires, the Roman empire, the Islamic caliphates, the Ottoman empire, the various European colonial empires and even the communist regime of the Soviet Union – all eventually fell. Even the United States’ global primacy, a logic result of the end of the Cold War, is now being tested by...