At the end of the twentieth century, two trends can be observed in international economic relations. On one hand, the reforms from the Uruguay Round have significantly increased the importance of the WTO's multilateral legal framework. On the other hand, the undeniable successes of the European Communities have greatly enhanced the attractiveness of forming regional preference zones. The study addresses these developments by comparing the integration model of the EC with the low level of integration of NAFTA and examining the impacts on the WTO's multilateral legal framework. The success of the EC is primarily attributed to the establishment of a strong legal framework that comprehensively regulates relations within the EC. In contrast, NAFTA is highly power-oriented and therefore problematic in its outcomes. Regarding the impacts on the WTO, the EC is largely unproblematic, while NAFTA and other regional preference zones with low levels of integration fundamentally challenge the WTO system.