Locusts, drought, crops crumbling into dust: in 2005, the Sahel was hit by a catastrophic food crisis. Eight million people were affected. Two years on, drought has eased in this arid strip south of the Sahara, but its people still live in the grip of extreme vulnerability. Their condition is a crisis in itself and a near-guarantee of more humanitarian disasters in the region, whatever the force or frequency of future shocks. Aid donors need to recognise this vulnerability as the root cause of the Sahel’s rolling crises.