Legal Processes of Change: Article 2(4) and the Vienna Convention on the Law of Treaties

Abstract:     
This article explores the various mechanisms through which the prohibition on the use of force in international relations found in Article 2(4) of the United Nations Charter might be changed. It identifies two principal mechanisms by which this might have happened: (1) formation of a new customary rule governing uses of force that overrules Article 2(4); and (2) a good faith interpretation of the meaning of Article 2(4) through state practice. It then examines several classic examples of apparent violations of the prohibition on the use of force to determine whether there has been any change.

The most striking finding is that uses of force, even those quite clearly in violation of Article 2(4), are usually accompanied by legal justifications that are consistent with Article 2(4). In many cases these legal justifications are inapposite and perhaps even disingenuous, but they lack the opinio juris that would be necessary to create a new customary rule on the use of force that would overrule Article 2(4). In addition, the majority of examples examined in this article could not be evidence of a good faith interpretation of the meaning of Article 2(4) because they were rejected by the majority of members of the United Nations. This leads to the conclusion that the meaning of Article 2(4) has probably not been changed by contradictory state practice.

Number of Pages in PDF File: 42

Keywords: use of force, Article 2(4), United Nations Charter, opinio juris, state practice, good faith agreement, pacta sunt servanda, Panama, Goa, Grenada, Libya, Czechoslovakia, self-defense, Article 51, customary international law, treaty interpretation

JEL Classification: K33

Accepted Paper Series