International law's duty of non-aggravation requires states to avoid actions that might inflame an international dispute, both to maintain international peace and to preserve the effectiveness of judicial or arbitral proceedings. Yet parties on the receiving end of calls for non-aggravation --whether from the Security Council or at tribunal -- have little idea of what conduct they are expected to avoid. This state of affairs is most unfortunate in light of the centrality of this norm to the peaceful resolution of disputes and, in particular, examples of seemingly provocative and aggravating acts in recent years. This article attempts to give some meaning to this important, but frustratingly vague, norm of international law. After reviewing current understandings of the duty by political and judicial bodies, it justifies the need for a more specific understanding of non-aggravation. It then develops a set of criteria to distinguish aggravating from non-aggravating acts, a process informed by both existing expectations and the underlying purposes of the norm. Based on these criteria, the article offers a coding scheme of presumptively aggravating and non-aggravating acts. Beyond its relevance for decision makers, the article seeks to encourage theoretical inquiry into the advantages and disadvantages of vague (or underspecified) norms in the international legal order.
Ratner, Steven R. "The Aggravating Duty of Non-Aggravation." European Journal of International Law, 31, no. 4 (2021): 1307-1342.