MEDIATORS from West Africa's regional bloc have arrived in Mali and started talks aimed at reversing a coup that has been condemned abroad, but celebrated by many in a country battling an Islamist insurgency and simmering political unrest. Leaders from the 15-nation Economic Community of West African States (ECOWAS) have taken a particularly hard line on Tuesday's ouster of President Ibrahim Boubacar Keita. They quickly shut borders and ended financial flows - a move diplomats said was as much about dissuading opponents at home as stabilising Mali. "They cannot tolerate this taking place. They are taking it very personally. It…