The youngest was 22, the oldest 43. France is mourning its loss in Mali. The 13 troops killed in the collision of two military helicopters on patrol making for the biggest single day casualty toll since 1983 and serving as a reminder that nearly seven years after the French military intervened to rout the jihadists who had taken over the north, Mali's insurgency has relocated south to the inhospitable area bordering Niger and Burkina Faso. Why the resurgence? What's the plan?