59. Legal Adviser William H. Taft IV's remarks regarding the use of force under international law (October 27, 2004)

Georgetown University Law Center Symposium — Inauguration of Eric E. Hotung International Law Center Building

Wednesday, October 27, 2004

“Role and Significance of International Law Governing the Use of Force in the New Global Context Confronting the United States After 9/11”


International Law and the Use of Force



Let me begin by thanking the Law Center for inviting me to participate in today’s symposium, as well as Professor Stromseth for chairing this program. I’m pleased to be here to discuss the role and significance of international law governing the threat or use of force after the attacks of September 11, 2001.




While the United States has given a lot of thought to the use of force after September 11th, our view of the fundamental principles regarding when force may be used and the manner in which it may be used have not changed. As in the past, so today the United States is prepared to deploy its forces, first, in self‑defense in the face of an actual or imminent attack and, second, in cases in which there is authorization by the U.N. Security Council. At the outset I should also say that the right to use force preemptively in self‑defense, which was affirmed in President Bush’s National Security Strategy, announced in September 2002, is not a novel concept in international law or in the history and experience of the United States. It is a natural adaptation of the concept of “imminence” to an era of weapons of mass destruction.

Let me elaborate these points.




The U.N. Charter restricts the use of force by states to resolve international disputes, but it expressly recognizes the “inherent right” of states to use force in self-defense. Article 51 of the U.N. Charter states that “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.” The United States has long held that, consistent with Article 51 and customary international law, a state may use force in self‑defense in the event of an actual or imminent attack.

Although the U.N. Security Council plays an important role in addressing threats to international peace, it is not always able to prevent or stop the use of force. The right of states to act individually and collectively in self‑defense is, therefore, a pillar of the international regime for maintaining and restoring international peace and security. One of the central purposes of the U.N. Charter is to prevent states from attacking other states, and a state is surely less likely to attack another state when it credibly expects the use of force in response by the other state, or the other state and its allies.

The events of September 11th clearly constituted an armed attack that required a military response in self‑defense. Indeed, in Resolutions 1368 and 1373, the Security Council reaffirmed the inherent right of individual or collective self‑defense and expressed its determination to combat, by all means, threats to international peace and security caused by terrorist acts. Secretary General Annan confirmed that the U.S.-led coalition “set their current military action in Afghanistan in that context.” Evidently, where a state uses terrorism to conduct an armed attack against another state, or allows its territory to be used as a base for such purposes, the state under attack has the same right to defend itself as it does when attacked by more conventional means.




Of course, it is also well established that states have the right to use force before an actual attack has taken place — when an attack is “imminent.” President Bush reaffirmed this right in his National Security Strategy: The United States will use force where it faces a credible, imminent threat and peaceful remedies have been exhausted. The use of force in advance of an actual attack should, however, be supported by careful, timely intelligence and any such action must be proportionate to the threat that is being confronted. The National Security Strategy stressed this point, too.

The National Security Strategy finally elaborated on the concept of imminence as it operates in an era of weapons of mass destruction. The right of self-defense could be meaningless if a state cannot prevent an aggressive first strike involving weapons of mass destruction. The right of self‑defense must attach early enough to be meaningful and effective, and the concept of “imminence” must take into account the threat posed by weapons of mass destruction, the intentions of those who possess such weapons and the catastrophic consequences of their use. The right to use force preemptively in situations involving weapons of mass destruction, as set out in the National Security Strategy, arises from considerations of these factors.


Security Council Authorization


Chapter VII of the U.N. Charter authorizes the Security Council to take “such action . . . as may be necessary to maintain or restore international peace and security.” The Security Council has invoked its authority under Chapter VII on many occasions to authorize the deployment of military forces in order to address threats to international peace and security. Recent examples include military action to disarm Iraq and the deployment of international security forces in Kosovo and East Timor.

As in the case where states act in self-defense, the Security Council should act deliberately and cautiously, considering always the possibility of peaceful remedies, before invoking Chapter VII to authorize the use of force to meet threats to international peace and security. If deliberative efforts and peaceful remedies do not, however, resolve the problem, the Security Council must be prepared to use its Chapter VII authority to resist acts of aggression and restore the peace. In some instances – particularly where a threat involves weapons of mass destruction – the Security Council may of course authorize the use of force preemptively, where doing so is necessary to maintain or restore international peace and security.


Rationales Considered but Not Adopted by the United States


Besides the use of force in self‑defense and in cases in which there is authorization by the U.N. Security Council, some states have proposed other rationales for the use of force. While we have considered them carefully and they have some merits, to this point the United States has not embraced them.

Of particular note, the idea that humanitarian catastrophes must be avoided has been asserted as a reason for rethinking what actions international law permits in a number of situations. NATO's intervention in Kosovo in 1999 is a case to consider in this connection. In defending the legality of NATO's actions, the United Kingdom and several other allies asserted a doctrine of humanitarian intervention, under which states have a right to use force if it is necessary to prevent genocide, a major loss of civilian life, or a large scale forced movement of a population, which would destabilize other states and threaten international peace and security.

In this view, the humanitarian intervention doctrine is often presented as a necessary extension of humanitarian law as it has evolved since 1945. Significantly, the doctrine was invoked in the absence of authorization by the UN Security Council. The United States did not, however, adopt this theory as a basis for the NATO intervention in Kosovo, and instead pointed to a range of other factors to justify its participation in the Kosovo campaign.

In considering the rationale for the use of force in Kosovo, states have been faced with a more general question. Is it better to have a very strict rule prohibiting the use of force that is in some rare cases simply not complied with or should we adopt a broader rule that attempts to anticipate those rare cases and approve them in advance generically? Advocates of a strict rule argue that states will inevitably interpret a broader rule too liberally; it is better, they say, to maintain a tight rule and accept that in limited contexts the rule might have to be broken. Others argue that having a rule that is admittedly imperfect, and that states are not expected to live by in every situation, undermines the credibility of the law, even while they acknowledge that agreeing on a rule that covers all cases wisely is extremely difficult.

Lastly, some argue that where a group of people is fighting against colonial domination or an alien occupation in the exercise of their right of self-determination, such groups have a right to use force in the same way as if they were engaged in an international armed conflict and acting in self defense. The Declaration of Independence sets out something close to this rationale, and the United States has traditionally been slow to condemn groups resorting to the use of force in wars of national liberation. Recently, however, many groups have too easily claimed the right to use force on this basis, and the reputation of this rationale has not been enhanced by the fact that those using it have often sought to justify not just the use of force as permitted by the laws of war, but terrorist acts. Such disregard for the basic humanitarian rules concerning necessity, proportionality, the requirement to minimize civilian casualties and so forth has given this rationale a very bad name and is never acceptable.




The United States has historically fought its enemies in accordance with international law and – following the attacks of September 11th – the United States remains committed to defeating terrorism in accordance with the rules of international law. The United States and the Security Council have expressly recognized the right of self-defense against terrorist actions, and the right to use force preemptively in self-defense in appropriate circumstances is well established.

Thank you.