We live in a pivotal time for international economic law. Emerging powers have ascended in prominence and the United States and Europe declined as economic and trading powers. China has become a rival to the United States. Economists tend to explain the shift from the angle of efficiency and innovation, while political scientists in terms of power, and more precisely market and economic power. This book provides a necessary complement to these analyses by assessing changes in law and legal institutions, and, in particular, these countries’ development of trade law capacity, which is linked to broader policy capacity, to interpret, apply, develop, and shape the rules of the game.