Kenneth B Ati-John and Ndine Wa‑Chiuta respond to an article by Ghana’s president, John Dramani Mahama Kenneth B Ati-John and Ndine Wa‑Chiuta respond to an article by Ghana’s president, John Dramani Mahama The president of Ghana, John Dramani Mahama, is right to argue that recognising the transatlantic slave trade as a crime against humanity is an essential step toward justice ( It’s time for the UN to formally recognise the transatlantic slave trade as a crime against humanity, 22 March ). But