Between 1750 and 1914, what the British historian Eric Hobsbawm called the “Dual Revolution” gave the West a sudden and enormous advantage over the rest of the world. Taking advantage of this shift in the balance of world power, Western countries returned with new energy to the policy of imperialism. By 1914, the Indian sub-continent and South East Asia had been subdued and Africa partitioned, while the rotting Ottoman and Chinese empires were next on the list. Political control went hand-in-hand with determined effort at economic and social Westernization. Christian missions, banks, schools, railroads and steamship lines, army posts and naval bases, mines, tropical medicine institutes, plantations, newspapers, tax collectors, and courts sprang up everywhere.
Half a century later, those empires were gone. How did that happen? Many factors played a role. The Second World War left Europe in ruins, while elevating two anti-colonial “Superpowers.” Relatively few Westerners had gone out to run the empires. Their sway over non-Western subjects depended heavily upon prestige, the sense that Westerners really were superior. The Japanese victories over Westerners in British Malaya, the Dutch East Indies, French Indochina, and the American Philippines showed that non-Westerners could defeat Westerners. After the war, European countries were preoccupied with using their limited resources for economic reconstruction and social reform. Finally, the war had been fought by the Westerners for the cause of individual liberty, human rights, and democracy. Faced with colonial independence movements after the war, they couldn’t say “For us, but not for you.”
Yet the Western collapse tells, at most, half the story. More important is the rise of support for independence movements. The colonial people had been no more happy to be subjugated to foreign rule than had African-Americans to be subjugated to slavery. How to respond to the Western challenge had long divided non-Westerners—from the American Plains to Central Africa to the Ottoman Empire to East Asia. One answer was to turn Western achievements against Western rule. This ran from wholesale imitation of the sources of power (Japan) to the exploitation of Western political thought, like the idea of nationalism, against those who claimed to represent it (India). Then the wars incidentally created a base of nationalists. They did so by accelerating the creation of a middle class and a cadre of experienced military leaders. Both groups were strongly nationalist and eager to rise.
Finally, there were the committed revolutionaries. Their numbers continually winnowed by the colonial police, they printed illegal newspapers and handbills, organized demonstrations and strikes, travelled within their homelands and between different empires using false documents, and sometimes led armed uprisings. These were the men who often would take office at the hand-over of power. They would try—with uneven success–to build new states.
 In politics this meant the emergence of strong centralized nation-states ever-more based upon the support of the governed. In economics this meant the Agricultural and Industrial Revolution, which generated immense wealth. The political revolution began in France, the economic revolution began in England. With the passage of time, both revolutions spread everywhere, simultaneously creating and destroying.
 For a compelling view of the British Empire at its height, see James (Jan) Morris, Pax Britannica: Climax of an Empire (1968).
 Tim Harper, Underground Asia: Global Revolutionaries and the Assault on Empire (2021). See the perceptive review by Walter Russell Mead, WSJ, 13 January 2021.