Our present-day world of nation states was born by accident. Nation-states haven't been ever present; nor were they the inevitable outcome of nationalism. Instead, from Indonesia to Iran to the United Kingdom—all new nation states in the late 1940s—they emerged out of the chaos which followed World War II.The nation state, we are told, was created in the West hundreds of years ago. It grew, so the story goes, from the steady development of national identities and as a triumphant product of Western political order and progress. Such oft-told stories are wrong. They are based on a fundamental misunderstanding of nations and nationalism, and the way in which the world we live in is organized today. In fact, our present global political order, with the nation state as its fundamental unit, is only as old as the postwar world: it emerged everywhere in the world at the same time, as the unplanned response to a moment of global crisis.Before the 1940s the world was organized into empires or federations. Few thought nations could be the basis of political order. Acclaimed historian Jon Wilson shows how the crises which followed the end of World War II up-ended common-sense ideas about how the world should be organized. In a truly global story with as much to say about what happened in Montevideo, Yogyakarta, New Delhi, and Jerusalem as New York or London, Out of Chaos shows how political leaders debating the postwar order ended up with an unexpected compromise: the partition of the people, territory, and economies of the world into nation states. It traces a truly global tale; of how ideas from Latin America were picked up in Indonesia; or of how Indian military officials shaped the fate of central Africa.Out of Chaos shows how the nation state emerged as the only form of organization political leaders from different ideological positions, from every continent, could agree on to manage the fractured, impoverished post-war world. This was not a political order created by any one power or ideology; there was never, for example, a US-led world order. The nation state was agreed by capitalist and communist states alike. The postwar world was multipolar from the start.From the middle of the twentieth century to now, nation states have been sustained by peoples' affection for the communities they live in. But the chaotic process of their emergence, with limited agreement about ideas, means other ideas about how to organize the world survive. Out of Chaos radically reframes how we think about the history of the twentieth century, showing that the conflicts of the present day are rooted in the process by which nation-states emerged from the postwar crisis.