West Africa has perhaps lulled outsiders into a false sense of security. The regional economy has grown fast and key countries like Nigeria, Ghana and Senegal have embraced democratic transitions. But the appearance of stability may be illusory. Boko Haram's militant insurgency threatens not just Nigeria, but neighbouring states, and poverty, corruption and repression are still endemic in these areas. Stephen Sackur speaks to the UN's special representative for West Africa Mohamed Ibn Chambas. How fragile is West Africa?