Why did Portugal hold its African colonies longest?

The short answer

• Empire and the dictatorship. For Salazar's dictatorship, empire was part of the claim that Portugal remained a great power. The colonies supplied resources, and settler emigration offered a safety valve. Portugal was Europe's poorest state, unlike the richer democracies of Britain and France, and its authoritarian government had no democratic means of turning public weariness with war into a new policy. Unable to imagine a post-imperial future, it fought for thirteen years after the rest of Europe had quit. The timing of withdrawal depended on the politics of the metropole.
• Cabral’s struggle. Amílcar Cabral approached liberation as an agronomist who had studied his people's social structure. In Guinea-Bissau he helped build liberated zones with schools and clinics, holding that the struggle was cultural as well as military. His instruction was “tell no lies, claim no easy victories.” The PAIGC controlled most of the countryside before Portugal conceded and came closest to outright military victory. Cabral, the era's most original revolutionary thinker, was assassinated in 1973, months before independence. The memorial marks the loss of one of Africa's finest minds.
• A revolution in the army. Portugal's own army brought the decisive break. Younger officers had served in a war they found endless and unwinnable; exposure to leftist ideas also shaped them. They concluded that the colonies could not be held and that the dictatorship conducting the war had to go. In April 1974 the Carnation Revolution overthrew it. The struggle for liberation in Africa had worn down the colonizer until a government fell in Europe.
• Foreign powers and Angolan rivals. The Angolan movements entered the struggle for power with different patrons: the MPLA leaned Soviet, while UNITA and the FNLA leaned toward the West and apartheid South Africa. As Portugal withdrew, the superpowers and Pretoria intervened. Cuban regulars and Soviet arms supported one side; South African armor and American money supplied opponents. These resources turned decolonization into a Cold War proxy battlefield. International involvement was central to the continuation of the Angolan and Mozambican wars for a quarter-century after Portugal left.

What it changed

A rapid withdrawal. Portugal recognized Guinea-Bissau in 1974. Mozambique, Angola and the island states followed in 1975. Once Lisbon decided to leave, the last major European empire on the continent dissolved almost overnight. Nothing had changed militarily in early 1974, yet a revolution in Portugal freed a continent's worth of colonies within eighteen months. Events in the colonizing country mattered as much to the pace of decolonization as conditions on the ground.

Wars after liberation. Angola and Mozambique emerged with Marxist governments aligned with the Soviet bloc. Apartheid South Africa and its allies moved to destabilize them, supporting UNITA in Angola and RENAMO in Mozambique. The resulting wars killed perhaps one and a half million people between them, mostly civilians, and mostly through famine and landmines. Liberation wars had given way to Cold War and apartheid wars of destabilization. The civilian dead belong at the center of this history.

The southern frontier changes. The independence of Angola and Mozambique removed a buffer around white-ruled Rhodesia and South Africa. Both now faced hostile neighbors and guerrilla bases on their borders. Mozambique's independence tightened pressure directly on Rhodesia; Angola's placed a Cuban army on Namibia's frontier. The collapse of Portugal's empire set the stage for the final struggle over the settler south. Scrub forward and watch the last charcoal shrink.