YJIL Online Symposium: A Response to A. Arend and L. Johnson

It’s an honor to have two so distinguished scholars comment on my article. As always, I learn from reading their commentary and I thank each for his insights.

Two quick reactions. First, Professor Johnson raises an interesting semantic question (which I do not address in the article): If a state “unsigns” a treaty, is it still a signatory? Professor Johnson is surely correct that a state cannot re-write history by purporting to expunge its signature as a matter of official record. Further, liability that a state incurs as a signatory to a treaty during a given period is not extinguished by a later decision to terminate signatory obligations; the state remains responsible for any action on its part that defeated the object and purpose of the treaty while it was subject to those obligations. On the other hand, a state that is a party to a treaty can under certain circumstances terminate that status and become a non-party. If a state terminates a treaty, it is no longer a party. One may well ask, therefore, why signatory status should be any different. Arguably, analytic clarity is advanced by thinking that signatory obligations and signatory status go together just as obligations under the norm of pacta sunt servanda and status as a party go together. When signatory obligations cease, signatory status might similarly end without altering the historical fact that the state was at one time a signatory. In any event, all this is a matter of terminology, not substance. No serious commentator, so far as I am aware, contends that by “unsigning” the Rome Statute the United States failed to make clear its intention not to become a party to the treaty. It did make that intention clear. The United States therefore terminated all signatory obligations under the treaty. (How a potential U.S. decision to unsign its unsigning might be described is beyond the scope of this post.)

Second, Professor Johnson’s unanswered questions concerning the relationship between the crime of aggression and the articles on state responsibility underscore my central conclusion ― which is the same as his and Professor Arend’s: the definition fails to provide ascertainable standards of guilt. For as Professor Johnson hypothesizes, a defendant charged with the crime of aggression might rely upon the “circumstances precluding wrongfulness” laid out in the articles, and neither the Rome Statute nor the articles provide any useful guidance as to what weight such a defense must be accorded. Moreover, as Professor Arend suggests, what constitutes a manifest violation of the Charter, and who is in a position to control or direct the action of the state, are both questions ― under the existing state of international law ― on which reasonable persons can differ. In this regard I recommend an incisive article by Professor Sean Murphy, “Aggression, Legitimacy and the International Criminal Court,” [http://www.ejil.org/article.php?article=1938&issue=93] in the current issue of the European Journal of International Law. Professor Murphy points out that the new definition would not be regarded as legitimate under the criteria identified by the late Professor Thomas M. Franck. He suggests that the definition’s indeterminacy ― the lack of clarity that leaves those to whom it might apply unable to understand it ― undermines the proposed crime’s pedigree and, ultimately, its probable compliance pull. The burden, I suggest, is now on the new definition’s proponents to show that persons of common intelligence would give the same answers to the many reasonable questions that have now been raised. If the proponents cannot tell us what those answers would be, it is fair to conclude that the definition does not pass muster under the principle of legality.