The conflict in the Sahel region of Africa is for much of the world - a forgotten war.
And yet last year alone 4,000 people there were killed in terror attacks. This year France is sending another 600 troops.
Violence has spread since extremists launched a campaign in Mali in 2012. It has since spilled over into Niger and Burkina Faso displacing hundreds of thousands from their homes.
In this week's episode, Tim Marshall examines the recent history of terror in the region, which has become the fastest growing Islamist insurgency in the world.
