THE BUSH DOCTRINE, as promulgated by President Bush following the events of September 11, contemplates preemptive use of force against terrorists as well as the states that harbor them. If the United Nations Charter is to be believed, however, carrying out that doctrine would be unlawful: The Charter permits use of force by states only in response to an armed attack. In 1945, when the Charter was framed, this prohibition against anticipatory self-defense may have seemed realistic. Today, it is not. Indeed, it is no longer binding law.
Since time immemorial, the use of force has been permitted in self-defense in the international as well as all domestic legal systems, and for much the same reason: With states as with individuals, the most elemental right is survival. So powerful has been its claim that the right of self-defense was considered implicit in earlier treaties limiting use of force by states; the Kellogg-Briand Peace Pact of 1928, like the 1919 Covenant of the League of Nations, made no mention of it.
In 1945, the right was made explicit. Article 51 of the United Nations Charter states expressly: "Nothing in the present Charter shall impair the inherent right of individual or collective self-defense if an armed attack occurs against a Member of the United Nations. . . ." Self-defense thus emerged as the sole purpose under the Charter for which states may use force without Security Council approval.
While the Charter professes not to "impair" the inherent right to self-defense, it does precisely that. Prior to 1945, states used defensive force before an attack had occurred, to forestall an attack. The plain language of Article 51 permits defensive use of force only if an armed attack occurs. If none has occurred, defensive force--"anticipatory self-defense"--is not permitted.
This new impairment of the right of self-defense was widely seen as sensible when the Charter was adopted. States had often used the claim of self-defense as a pretext for aggression. (The Nazi defendants at Nuremberg argued that Germany had attacked the Soviet Union, Norway, and Denmark in self-defense, fearing that Germany was about to be attacked.) If profligate use of force was ever to be reined in, narrower limits had to be imposed. And those limits had to be set out with a bright line; qualifying defensive rights with words like "reasonable," "imminent," or even "necessary" would leave states too much discretion and too much room for abuse. The occurrence of an actual armed attack was thus set up as an essential predicate for the use of force. The new requirement narrowed significantly the circumstances in which force could be used. And it set out a readily identifiable and, it was thought, objectively verifiable event to trigger defensive rights. Phony defensive justifications would be less plausible and war would be less frequent, thereby vindicating the first great purpose of the Charter--"to maintain international peace and security."
The impairment was realistic, it was further thought, because the need for anticipatory defense would diminish. The reason was that the Security Council would pick up where individual states were now compelled by the Charter to leave off. The Council, to be equipped with its own standing or standby forces, was authorized to use force in response to any "threat to the peace"--authority far broader than that accorded individual states. Coupled with the requirement that states report to the Security Council when using defensive force, this new institution--this "constabulary power before which barbaric and atavistic forces will stand in awe," as Churchill described it--would make anticipatory self-help a thing of the past.
All know that it didn't work out that way. Throughout the Cold War the Security Council deadlocked repeatedly on security issues. States never gave the Council the peace enforcement troops contemplated by the Charter's framers. The Council authorized (rather than used) force only haphazardly "to maintain or restore international peace and security." And, as discussed later, states continued to use force often, obviously not in response to armed attacks.