Afua Hirsch examines the principle of self-determination, which Franklin Roosevelt insisted on including in the Atlantic Charter. It was a powerful force behind the liberation struggles which peaked in the 1950s and '60s as a wave of decolonisation swept the world and countries such as Tunisia, Jamaica, Nigeria and Guyana achieved independence. But it is not the same as a right to separate and form your own country, as the Catalans have recently been reminded. And it has a forgotten dark side as a justification for population transfer, going back to 1923 when Greece and Turkey agreed to uproot two million people in a forced population exchange.

Presenter: Afua Hirsch

(Photo: Illustration of a knitted ball resembling Earth unravelling. Credit: Nadia Akingbule)