In Principle but Not in Practice: The Expansion of Essential State Interests in the Doctrine of Necessity under Customary International Law

Article excerpt


Suppose that two sailors, A and B, are shipwrecked in the middle of the ocean. Both sailors simultaneously notice a floating plank, but it is only big enough to support one of the two men. Exhausted, Sailor A swims to the plank first, but Sailor B, facing certain death, decides to push A off of the plank and A drowns. Does B have a legally valid defense for his actions? Around 155 B.C., the Greek philosopher Carneades set forth this hypothetical situation, known today as "the plank of Carneades," to posit that strict necessity could serve as a valid defense for an otherwise unlawful action. (1) Indeed, the concept of necessity in law is as old as Western society itself.

Over the years, the doctrine of necessity has moved beyond the municipal realm, and now plays an integral role in the law of nations. Regardless of whether the defense of necessity is a stated exception to the laws of war or a post facto excuse for a breach of international obligations, essential state interests are at the heart of the doctrine's invocation and application. Until the late twentieth century, a state's "essential interests" were limited to those necessary to maintaining the existence of a state in the face of foreign or domestic violence of a military nature. This paper explores the expansion of the concept of essential state interests during the late twentieth century, as it grew to include both ecological and economic interests. Surprisingly, this nominal expansion did little in the way of expanding the applicability of the doctrine of necessity as a whole.

Part II tracks the historical development of the doctrine of necessity under customary international law from a mere diplomatic pronouncement to a formally recognized doctrine capable of overriding express treaty obligations. Part III expounds upon the role of essential state interests in the modern application of the doctrine of necessity, showing that their primary function is to limit the use of the doctrine. Part IV shows that the initial expansion of essential state interests to include ecological interests, as seen in the Case Concerning the Gabdlkovo--Nagymaros Project, will not likely lead to a near term increase in the successful use of the doctrine to protect such interests. Part V moves from ecological interests to economic ones, and seeks to explain the dichotomy in the International Centre for the Settlement of Investment Dispute's ("ICSID") holdings in CMS v. Argentina and LG&E v. Argentina; the former ruled that the Argentine financial crisis of the late 1990's created a state of necessity while the latter ruled that it did not. Part VI suggests that ICSID jurisprudence following the CMS and LG&E is proof that economic interests, despite their characterization as "essential state interests" in LG&E v. Argentina, will not lead to an expansion of the successful use of the doctrine. Part VII discusses the future of the doctrine of necessity as it relates to ecological and economic necessity. Part VIII concludes.


The first case to mention the concept of necessity in the context of international law was in fact not a case at all. Rather, it was a diplomatic dispute between Great Britain and the United States of America. Nevertheless, "[i]t was in the Caroline Case that self-defence was changed from a political excuse to a legal doctrine." (2) Accordingly, the modern doctrine of necessity under customary international law can be traced directly to the end of the Canadian Rebellion of 1837. (3)

After the Canadian insurgents had been largely defeated, two rebels, McKenzie and Rolfe, travelled to Buffalo, New York where they assembled a force of several hundred men to carry out a rebellion. (4) The group, made up primarily of American citizens, openly invaded and took control of Navy Island, a possession of the British, and held the island for seventeen days. …