The book presents a history of the evolution of this 3000-km frontier, and then inquires into the smuggling of contraband: who smuggled and why, what routes were favored, and how effectively the British and Dutch were able to enforce their economic, moral, and political will. Examining the history of states and smugglers playing off one another within a hidden but powerful economy of forbidden cargoes, the book also offers new insights into the modern political economies of Southeast Asia.