This report examines how vulnerability is understood and addressed by development agencies and government departments in Mali, Niger and Burkina Faso. The 2005 food crisis highlighted the extent of vulnerability in the Sahel region, increased international attention paid to the people of the Sahel and led to large sums of money being released to help those people survive the immediate crisis. Most studies written in the aftermath of the crisis have looked at the particular circumstances of the events of 2005. This report was commissioned by the Sahel Working Group, which was concerned that too much attention has been paid to a quite specific scenario and too little to the unacceptable and growing levels of vulnerability that pre-dated the crisis and persist two years later. The report is divided into four main sections. The first explores the meaning of vulnerability as perceived by theorists and development practitioners in the context of the Sahel and identifies who is most vulnerable. The second part assesses the root causes of vulnerability in the Sahel. It considers a wide range of critical and interlocking factors that lead to so many people being vulnerable. The third section reviews aid delivery mechanisms adopted, and the impact these have had on vulnerability. The final section raises a set of conclusions and sets out a number of key recommendations that emerge from the overall report, as follows.