Crimes of War

September 21, 2001

Michael Matheson
Senior Fellow, U.S. Institute of Peace

What is the best terminology for the international legal aspects of the recent attacks and the possible U.S. response? The Administration has used the term “act of war”, which is a term dating back to the period before the UN Charter and referring to armed acts of one state against another. I think the term is being used now more in a political than a legal sense – that is, that the recent attacks are comparable in magnitude and kind to traditional warfare between states and require a comparable response. The UN Charter does not use this language, but instead prohibits the use or threat of force by one state against another, preserving the right of each state to act in self-defense in the event of armed attack. This, I think, is the terminology to use in discussing the international legal questions.

The attacks in New York and Washington appear to have been conducted by terrorists who do not constitute the government of a state. Of course, this has happened before: the most conspicuous recent examples involving the United States were the bombing of the U.S. embassies in East Africa in 1998 and the October 2000 attack on the USS Cole off the coast of Yemen. In principle, these attacks are much the same, except of course that the loss of life in the September 11 assaults was much greater.

These recent attacks appear to fall within the category of international crimes. The hijacking and destruction of civil aircraft violate the Montreal Convention. They may also constitute “crimes against humanity”, in that they were serious acts of violence that appear to have been directed against Americans as a national group. Of course, they also violate a variety of U.S. laws, and under international law the United States has the right to prosecute any individuals who were involved in planning and carrying out these crimes, provided it can obtain jurisdiction over them, just as it had the right to try persons who were involved in the East Africa bombings.

The main question under international law is the extent to which the United States may now use force in foreign territory against the suspected terrorist network or states which may have supported it. The Administration appears to be planning for the possibility of such action, particularly with respect to the Bid Laden network in Afghanistan.

The Security Council has the power, under Chapter 7 of the UN Charter, to authorize such action if it determines that the situation constitutes a threat to international peace and security. In its decision on September 12, the Council did determine that the attacks in New York and Washington constituted such a threat, but did not expressly authorize the use of force in response. It is not at all clear that the Council would expressly authorize the United States to use force in another state, given the attitudes of China and some other members of the Council.

Nevertheless, the United States retains the right of self-defense, which needs no authorization by the Council. In fact, NATO has already invoked the provisions of the NATO Charter in characterizing the attack on the United States as an attack on all NATO members. Strictly speaking, this does not obligate NATO members to use force to assist the United States, but they would presumably feel obliged to at least give other forms of assistance, such as overflight rights and material support.

Does the United States have the right to use force against the bin Laden network, if it turns out that he was in fact behind the recent attacks? The United States has always maintained that it has the right to take armed action against private terrorist groups that attack or threaten U.S. citizens, if the state in whose territory they are operating is unable or unwilling to prevent such terrorist attacks. I think this is correct, provided that U.S. actions are necessary, proportionate, and in compliance with the law of armed conflict.

Would the United States have the right to use force against the state itself under such circumstances? This is more complicated, and in my view depends on the degree to which the state is involved in or tolerates the terrorist operations mounted from its soil. For example, during the 1980s the Lebanese Government was wholly unable to control the terrorist actions of militias on its territory against U.S. forces and citizens, even though it strongly opposed them. In that case, it would be hard to argue that the United States had the right to use force against the Lebanese Government, though it had the right to respond directly against the militias.

On the other hand, if the state in question refuses to take actions in its territory that it has the ability to take in order to prevent terrorist acts, then it bears international responsibility for further acts committed by that group. For example, the International Court of Justice found that Iran was liable for the actions of the militants who in 1979 seized the U.S. Embassy and took hostages, since Iran clearly had the ability to terminate their occupation of the embassy, but in fact supported and encouraged it.

I don’t know exactly where the situation in Afghanistan falls in the spectrum between the Lebanese and Iranian cases. But in my view, a state which supports, tolerates, or assists a terrorist group can be targeted in self-defense to the extent that this use of force might be necessary to prevent further attacks. This will, however, be a controversial proposition in international circles, and some states will probably take the position that one state cannot use force against another in such circumstances without the authorization of the Security Council. This – along with important political considerations – would make it very desirable to get as much authorization and sanction from the Council as is possible before acting.

Finally, the attacks in New York and Washington will not be within the jurisdiction of the International Criminal Court, when it comes into being; among other things, the Court’s jurisdiction is prospective only. However, the Security Council could, if it chose, give jurisdiction over these actions to the ICC or to an ad hoc tribunal, as it has done with respect to Yugoslavia and Rwanda. I don’t know whether this would be at all likely or whether the United States would favor such action.