Fighting the Hydra

In the past 25 years, the United Nations has sanctioned 28 rebel groups in 13 civil wars. Have the UN sanctions been effective in meeting the goal of conflict reduction? In this article, we argue that UN sanctions are effective to the extent that they can constrain and weaken some rebel groups. But this constraining effect can only occur when UN sanctions curtail rebel groups’ ability to adapt. For less adaptable groups, UN sanctions can trigger a causal chain of depressed rebel income, territorial losses, and battlefield defeats that leads to conflict reduction. This adaptability is the key to the understanding of UN sanctions’ effectiveness in conflict reduction, as rebel groups often engage in illegal and criminal economic activities and many of them are ‘Hydra-like’, being able to shift their income sources in response to sanction measures. As evidence of how UN sanctions can trigger these conflict dynamics, we first perform negative binomial regression on all civil war cases. We then proceed to provide more detailed evidence for our causal chain by conducting time-series intervention analysis on two sanctioned rebel groups: UNITA in Angola and al-Shabaab in Somalia. Our work is the first systematic quantitative analysis of UN sanctions’ effects on rebel groups, and the results have implications for the viability of economic coercion as a means to intervene into civil conflicts.