Mali’s former Prime Minister Ibrahim Boubacar Keita has won the presidential election runoff. He now faces a tough task of rebuilding a country reeling under more than a year of turmoil including a military coup and war. Mali’s first election since 2007 was seen as vital for unlocking more than $4 billion in aid promised by international donors who halted contributions in the wake of last year’s coup that ignited an Islamist insurgency and a French military offensive.