Justifying force: international law, foreign policy decision-making, and the use of force

Abstract

What is the role of international law in foreign-policy decision-making? In particular, why do leaders justify policy decisions with appeals to international law and why do these appeals make the references that they do? This paper combines scholarship on the role of justifications and the permissive power of international law, theorizing that decisionmakers will seek out international legal justifications over justifications that reference non-legal claims. These justifications are seen as particularly important in the contemporary world, reflecting the legalized nature of international relations today. In particular, decision-makers will especially prefer to reference codified international agreements over customary international law, seeing a particular value to referencing a written text even if it is not as directly connected to the issue at hand. These more general justifications are, in turn, preferred over non-legal justifications. This reflects the importance of international law in international relations—in a deeply legalized system actors feel compelled to portray their behaviors as legal, even if these justifications are tenuous or if pursuing them is time and resource consuming. The United Kingdom’s 1956 intervention in the Suez and the United States’ 1983 intervention in Grenada—are used to test these assumptions. Both cases support the theory: decision-makers prefer legal justifications, pursuing these over other options. In addition, decision-makers appear to prefer legal arguments built on codified law, keeping with the theoretical predictions. These findings deepen our understanding of how actors understand and use international law, its role in justifications, and the legalized nature of international relations today.