The Morality of Substitution Intervention: The Case of Yemen

Throughout the Yemeni Civil War, western states have supplied weapons used in the indiscriminate bombing campaign conducted by the Saudis. In defence of their actions, British politicians have argued that they are exchanging weapons for influence, and using the influence obtained to encourage compliance with humanitarian law. An additional premise in the argument is that Britain is using its influence more benignly than alternative suppliers would use theirs if Britain were not on the scene. The idea is that Britain is substituting itself for other, less scrupulous, interveners. I argue that, regardless of whether British substitution intervention could be justified in this way, it is not in fact justified, because Britain has not plausibly used its influence to secure an amount of good sufficient to offset the various harms that its actions have created (or to discharge the expanded duties of rescue that greater influence entails). In addition, the paper identifies the various forms that substitution intervention can take, and shows how the concept reveals hitherto neglected reasons to both support and oppose intervention in foreign conflicts.