This book explores the impact of WTO law on domestic regulatory autonomy. It identifies and critically analyses the mechanisms working in WTO law that cause increasing interferences with domestic law and thus restrain the regulatory autonomy of the WTO members. The book proposes ways in which WTO law be conceptualised to enhance the policy space of WTO members. Therefore, the book demonstrates the flexibilities in interpreting and applying WTO core principles and provisions and explores interpretive and institutional conceptions that could serve as a pathway to allocating greater policy leeway to WTO members. With the re-alignment of the relationship between the WTO and its members, particularly in light of the Trump administration's arguably more adversarial stance, this book is to be much welcomed.