Unilateral Recourse to Military Force Against Terrorist Attacks

Abstract

If a state that has been victimized by a large-scale terrorist attack seeks recourse to military force against another state, it can be expected to do so at a scale well above the threshold set by Article 2(4) of the Charter of the United Nations. Such threat or exercise of military force is prohibited by that rule unless it is authorized under the provisions on collective security laid down in Chapter VII of the U.N. Charter or unless it occurs in legitimate self-defense. Under Chapter VII, it is for the multilateral decision-making of the Security Council to qualify a terrorist attack as a "threat to the peace" and then to decide what remedy is appropriate. The question to be discussed in this paper, however, refers to the legality of "unilateral" acts of military force in response to terrorist attacks. The discussion will therefore have to address the self-defense exception to the general prohibition on the use of force. Unilateral acts, it should be added, are here understood to include "plurilateral" acts, that is, acts undertaken by two or more states.