The Moral Basis of Humanitarian Intervention

This article discusses the moral principles underlying the idea of humanitarian intervention. The analysis is in two parts, one historical and the other philosophical. First, the article examines arguments made in late medieval and early modern Europe for using armed force to punish the violation of natural law and to defend communities from tyranny and oppression, regardless of where they occur. It seeks to understand how moralists writing before the emergence of modern international law conceived what we now call humanitarian intervention.

In the context of international law, humanitarian intervention is usually understood to be an exception to the nonintervention principle. However, the natural law tradition regards international law as less important than the moral imperative to punish wrongs and protect the innocent.

Second, the article considers how humanitarian intervention is justified within the reformulation of the natural law tradition displayed in recent efforts to theorize morality along Kantian lines. In this reformulation, humanitarian intervention is a product of the duty of beneficence and, more specifically, of the right to use force to protect the innocent. The article draws upon the biblical injunction “Thou shalt not stand idly by the blood of thy neighbor,” which has become a centerpiece of the modern reformulation, and briefly explores its application to humanitarian intervention in the context of international relations today. This reformulation of natural law explains why, despite modern efforts to make it illegal, humanitarian intervention remains, in principle, morally defensible.