Articles

• Mallard, Grégoire

Abstract

In recent years, international lawyers have increasingly debated the normative consequences of the ‘fragmentation’ of international law. More rarely have they studied empirically how tensions between overlapping systems of rules emerge, how conflicts are harmonized, and with what effects. This article explains such dynamics in the case of the nuclear non-proliferation regime (NPR) complex. Based on original archival fieldwork conducted in the private papers of American and European diplomats in the early Cold War, it shows how Western states solved the tensions that existed between contradictory commitments contracted in the European Atomic Energy Community (Euratom) Treaty and the Nuclear Non-proliferation Treaty in 1968 (NPT). To lessen the tensions between regional and global orders, the Euratom control rules were used as a source of inspiration for the new rules used to monitor compliance with the NPT at the global level. In retrospect, this outcome was puzzling, as the Euratom Treaty was not originally concerned with non-proliferation issues. That the knowledge of the original intentions behind Euratom was lost to the policymakers who negotiated the NPT thus had grave consequences in the future. This case shows the importance of studying the concrete knowledge of international legal rules that gets transmitted across generations of policymakers in order to understand how regime complexity evolves.