One of the last acts of former President Barack Obama's administration was to remove US sanctions against Sudan - with the proviso that this would take effect in six months if the regime of President Omar al-Bashir improved human rights and reduced conflict in Darfur. When South Sudan excised itself from Sudan in 2011, the government in Khartoum thought it would be quickly rewarded by the removal of American sanctions against the country. Nothing happened until Obama's December 2016 announcement. How did Khartoum go about trying to change US policy?