Hisham Matar's memoir The Return, which won the 2017 Pulitzer Prize for Biography or Autobiography. Gaddafi's government's treatment of non-Arab Libyans came in for criticism from human rights activists, with native Berbers, Italians, Jews, refugees, and foreign workers all facing persecution in Gaddafist Libya. Human rights groups also criticized the treatment of migrants, including asylum seekers, who passed through Gaddafi's Libya on their way to Europe. Despite his vocal opposition to colonialism, Gaddafi was criticized by some anti-colonial and leftist thinkers. The political economist Yash Tandon stated that while Gaddafi was "probably the most controversial, and outrageously daring (and adventurous) challenger of the Empire" (i.e. Western powers), he had nevertheless been unable to escape the West's neo-colonial control over Libya. During the Civil War, various leftist groups endorsed the anti-Gaddafist rebels—but not the Western military intervention—by arguing that Gaddafi had become an ally of Western imperialism by cooperating with the War on Terror and efforts to block African migration to Europe. Gaddafi's actions in promoting foreign militant groups, although regarded by him as a justifiable support for national liberation movements, was seen by the United States as interference in the domestic affairs of other nations and active support for international terrorism. Gaddafi himself was widely perceived as a terrorist, especially in the US and UK. Posthumous assessment International reactions to Gaddafi's death were divided. US President Barack Obama stated that it meant that "the shadow of tyranny over Libya has been lifted," while UK Prime Minister David Cameron stated that he was "proud" of his country's role in overthrowing "this brutal dictator". Contrastingly, former Cuban President Fidel Castro commented that in defying the rebels, Gaddafi would "enter history as one of the great figures of the Arab nations", while Venezuela's Hugo Chávez described him as "a great fighter, a revolutionary and a martyr". Former South African President Nelson Mandela expressed sadness at the news, praising Gaddafi for his anti-apartheid stance, remarking that he backed Mandela's African National Congress during "the darkest moments of our struggle". Gaddafi was mourned as a hero by many across sub-Saharan Africa; The Daily Times of Nigeria for instance stated that while undeniably a dictator, Gaddafi was the most benevolent in a region that only knew dictatorship, and that he was "a great man that looked out for his people and made them the envy of all of Africa". The Nigerian newspaper Leadership reported that while