Download this Paper Open PDF in Browser

Paper Charter: Self-Defense and the Failure of the United Nations Collective Security System

131 Pages Posted: 20 Jan 2007  

Robert J. Delahunty

University of St. Thomas School of Law (Minnesota)


The inherent right of individual and collective self-defense, recognized in Article 51 of the UN Charter, has come in for sustained scrutiny in recent years. Two interpretative tendencies - moving in opposite directions - can be observed. On the one hand, the United States government has argued for a broadened understanding of the article 51 right, contending, e.g., that it should be construed to permit self-defense in a range of circumstances in which an armed attack has neither occurred nor is imminent. On the other hand, the International Court of Justice (ICJ) has taken an increasingly restrictive view of Article 51 and the customary norms associated with it, e.g, by construing it to prohibit self-defense against attacks that do not reach a certain level of gravity or whose source is not identified by convincing evidence. The former trend gives great weight to the risk of attack by rogue states or terrorist groups sponsored by them; the latter trend emphasizes the risk that in the absence of substantial legal constraints, powerful states will be too prone to take recourse to violence.

This article argues that the choice between these conflicting interpretative trends must take greater account of the fact that the United Nations Charter is an integrated whole: Article 51 is not a freestanding provision, and cannot be read in isolation from the other clauses and overall structure of the Charter. Rather, Article 51 is a carve-out from a broader scheme of peace-maintenance through the collective security system that the Charter was designed to embody. Although the original intent of Article 51 was and remains vigorously disputed, it is plausible to construe it as imposing fairly severe restrictions on the right of self-defense previously recognized by international law. States that accepted those and other limitations on their traditional prerogatives with respect to war and peace when they ratified the Charter acted in reliance on the belief that the Charter's scheme of collective security would afford them at least as much protection for their national security as they had agreed to relinquish. In the event, however, that belief has proven to be badly mistaken: the Charter's collective security system has hardly ever worked (Korea and Gulf War II being the main - arguable - exceptions), and the post-Charter world has been marked by the persistence of war.

Given that the nations of the world cannot rely on the Charter's collective security system to protect them from attack, they would be relieved of any legal obligation to accept the limits prescribed by Art. 51, as construed by the ICJ, when considering the legality of proposed measures of self-defense. Instead, they would be entitled to resume their pre-Charter right of self-defense and even, in light of changed circumstances, to seek to develop more permissive customary norms.

If the Charter's use of force régime is rejected, however, there remains the question of how collective action against threats to or breaches of the peace can be organized, and what legal rules should regulate such interventions. The question is ultimately one of designing international institutions that combine both legitimacy and effectiveness. None of the currently favored mechanisms for stabilization through the use of force manages to combine legitimacy and effectiveness in satisfactory ways: these defective mechanisms include the Charter system itself, the use of regional security alliances such as NATO, or ad hoc coalitions of the willing led by the United States. Pending a satisfactory solution to the problem of designing an acceptable international régime governing the use of force, the United States' policy of acting multilaterally if possible, but unilaterally if necessary will and should continue to be followed.

Keywords: United Nations, international law, international security, collective self-defense, Article 51, United Nations Charter, law of war

Suggested Citation

Delahunty, Robert J., Paper Charter: Self-Defense and the Failure of the United Nations Collective Security System. Catholic University Law Review, 2007; U of St. Thomas Legal Studies Research Paper No. 07-01. Available at SSRN:

Robert J. Delahunty (Contact Author)

University of St. Thomas School of Law (Minnesota) ( email )

MSL 400, 1000 La Salle Avenue
Minneapolis, MN Minnesota 55403-2005
United States

Paper statistics

Abstract Views