The Notion of ‘Armed Attack’ in the Nicaragua Judgment and Its Influence on Subsequent Case Law

Abstract

AbstractThe notion of ‘armed attack’ is at the heart of the law on the use of force in self-defence. The ICJ first addressed the issue in its judgment in Nicaragua; however, its formulation of the legal parameters of ‘armed attack’ has not been without controversy. In particular, the high threshold of force required for an ‘armed attack’ and the consequent distinction between ‘armed attack’ proper and acts of lower intensity (termed ‘frontier incidents’) is said to have reduced the barrier to armed aggression. More recently, the formulation has also been criticized for not being fully applicable to large-scale terrorist attacks such as the events of 11 September 2001. This article examines the Court's first pronouncement on the concept of armed attack, with a specific focus on the rationae materiae aspect of ‘armed attack’, which situates it in the context from which it arose and analyses its development through subsequent case law, particularly the Court's judgments in Oil Platforms and Armed Activities (Congo v. Uganda) and the decision of the Eritrea–Ethiopia Claims Commission.