David Cameron has made another break with the Tories' past, admitting that Margaret Thatcher been had been wrong to brand Nelson Mandela's African National Congress "terrorists" during the struggle against apartheid in South Africa. Writing in The Observer, the Conservative leader praised the former president - whom he met on Wednesday during a visit to Johannesburg - as "one of the greatest men alive". "The mistakes my party made in the past with respect to relations with the ANC and sanctions on South Africa make it all the more important to listen now," he wrote. "The fact that there is...