Straits are peripheral formations in the study of geography, but have long been a source of controversy in international relations. They connect separate seas and divide the territory of states. This geographical fact invites legal disputes over international boundary drawing, request for passage by foreign ships, assertion of territorial control over the waters forming straits, and the basis for a regime generally accepted as law in our times. This is a thorough and well-documented book which combines elements of history, geography, international shipping, and the law of the sea. It asks the central question: what exactly is the current law governing this area, and also goes on to consider the concept of international straits, the distinction between existing treaty-based regimes and the general regime, and the special characteristics of straits that separate them from similar arms of the sea in terms of law. In answering these questions, the author takes us back to the first regime for international straits in 1949, through to the practices of the present day. This will be an invaluable text for all international lawyers, particularly those specializing in the law of sea.