From Bilateral to Multilateral Law-Making : Legislation, Practice, Evolution and the Future of Inter Se Agreements in the WTO

Among the innovations accompanying the transformation of GATT into the WTO was the remarkable strengthening of multilateral institutions. While the paradigmatic change brought about by the institutionalization of the multilateral trading system has been generally acknowledged, its impact on WTO law-making has been largely overlooked. Much of the debate has concentrated on whether and to what extent ‘external' international legal rules should be taken into account by WTO adjudicators. An analysis of the WTO jurisprudence, however, evidences a different approach. The interpretation (and, to some extent, modification) of WTO rules depends not on the bilateral relations between the parties to a particular dispute, which may affect the application as between them of the multilateral rules, but on the establishment – through subsequent agreement, subsequent practice, or broader normative evolution – of a ‘common understanding' of the membership. Once established, a new interpretation is not limited to the context of a particular dispute, but affects the WTO rights and obligations of all members. As a result, the bilateral logic that ordinarily determines legal relations between states based on individual consent gives way to a multilateral logic, which allows a degree of normative change while preserving the integrity of the WTO legal system