The dominant story of transboundary environmental impact assessment in international law has the following elements: (1) customary international law prohibits transboundary pollution; (2) according to the classic version of this prohibition, contained in Principle 21 of the 1972 Stockholm Declaration, states must ensure that activities within their territory or under their control do not harm the environment beyond their territory; (3) to ensure that activities within their jurisdiction will not cause transboundary harm, states must assess the potential transboundary effects of the activities; and (4) to that end, states enter into international agreements requiring them to carry out transboundary environmental impact assessment (transboundary EIA) for activities that might cause transboundary harm. Despite its popularity, this story is not true. It belongs to what Daniel Bodansky has called the "myth system" of international environmental law: a set of ideas that are often considered part of customary international law but do not reflect state practice and, instead, "represent the collective ideals of the international community, which at present have the quality of fictions or half-truths."' European and North American countries are adopting regional agreements that provide for transboundary EIA.(2)But these agreements do not require transboundary EIA for all activities that might cause transboundary harm, and they do not link it to any hard substantive prohibition against transboundary harm. In short, these agreements do not much resemble the mythic story of transboundary EIA. At the same time, the agreements are not meaningless. They require EIA for certain types of actions, specify the elements an EIA must include, and provide for significant public participation in the EIA process. What, then, is going on? If transboundary EIA agreements are not designed to end transboundary pollution in accordance with Principle 21, what are they designed to do? One clue is that the agreements were not written on a clean slate. Most countries in North America and Western Europe have already enacted domestic EIA laws, which are limited in scope and lacking in substantive prohibitions but do contain detailed procedural obligations and provide important avenues for public participation. In large part, the regional EIA agreements reflect these domestic EIA laws. In fact, the main way that the agreements extend beyond the domestic laws is by ensuring that states apply EIA without extraterritorial discrimination-that they take extraterritorial effects into account just as they take domestic effects into account, and that they enable foreign residents to have access to the domestic EIA procedures to the same extent as local residents. Another principle in international environmental law describes exactly this approach: the principle of nondiscrimination, which says that countries should apply the same environmental protections to potential harm in other countries that they apply to such harm in their own. Examined closely, each regional transboundary EIA agreement is an application of the principle of nondiscrimination. The nondiscrimination principle has often been overlooked, cast into shadow by the glow surrounding Principle 21, which is generally considered to be the cornerstone of international environmental law. But Principle 21 suffers from serious weaknesses as a cornerstone of international law, not the least of which is that it does not seem to be a law at all. Perhaps it would be more appropriate to think of it as a capstone that has never been set. Despite limitations of its own, the principle of nondiscrimination may provide a better blueprint for the EIA agreements. In part I of this article, I describe two stories of transboundary EIA: the mythic view of transboundary EIA as a corollary to Principle 21, and a more mundane view of transboundary EIA as an offshoot of domestic EIA laws. In part II, I show how the two regional agreements on transboundary EIA do not support the mythic view of transboundary EIA and, instead, extend domestic EIA in accordance with the principle of nondiscrimination. I also examine the International Law Commission's draft articles on prevention of transboundary harm,(3.) which hew much more closely to the mythic view. In part III, I defend the usefulness of the regional EIA agreements. I conclude with some brief observations oil the danger of confusing the myth of Principle 21 with the reality of international law.
