The military-ruled West African states of Mali, Niger and Burkina Faso plan to set up a joint force to fight Islamist terrorist groups. The force should be “ready for action as soon as possible,” Niger’s Chief of Staff General Moussa Salaou Barmou said during a televised address on Wednesday night. The aim was to work together “to overcome the security challenges facing the three countries,” the geneeral said. Niger, Mali and Burkina Faso formed a joint defence alliance – the Alliance of Sahel States (AES) – in September. Barmou said the new anti-terrorist task force will be integrated into th…