For the last three months I’ve been in Johannesburg helping to curate an exhibition of photographs at the Nelson Mandela Centre of Memory, part of the Mandela Foundation. On the Frontline looks back over the difficult years, from 1975 to the early 1990s, when South Africa’s neighbours gave their support to the liberation movements in South Africa – both the ANC and the Pan-Africanist Congress – and the South-West Africa People’s Organisation, in return for harsh treatment by the apartheid regime. Julius Nyerere of Tanzania, Kenneth Kaunda of Zambia and other leaders acted on the conviction that their newly won freedom was illusory until apartheid was a thing of the past.