This book provides a comprehensive review of the theory of international trade and trade policy, including coverage of recent areas of research such as heterogeneous firm trade models and trade costs. It then proceeds to analyze the history of trade policies and the evolution of the global trading system, with a primary focus on important policies or controversial issues such as the Doha Round, antidumping duties, regionalism and fair trade.It aims to emphasize the significance of different theories and how they are interconnected. Unlike other technique-driven international economics textbooks, this book focuses on readers understanding how theory and policy are connected. Written in a lecture note format and in a straightforward manner, the presentation is self-contained with no assumed mathematical knowledge.