The book emphasizes geopolitical rivalries in the Middle East and their consequences on key sea waterways in the region that connects the world's major maritime and land spaces. In addition to the analysis of their geography, main navigation patterns and potential difficulties, each chapter has been set in their respective economic, political and international contexts, enriched with maps that illustrate in detail specific historical situations. Over the course of history, powers have attempted to exercise various degrees of control over these important waterways. In the context of geopolitical and geoeconomic rivalries, state actors that are situated on or close to these waterways have played an important role in shaping maritime security in the region. Each of the situations is discussed separately, but it is common for links to be drawn between them as well. It has been historically observed that the importance of different sea routes and land itineraries has been greatly influenced by the dynamics of centers of wealth, culture, and power, whether regional or global. Thus, relations between and among these waterways have been characterized by periodic rises and declines, often affected by external factories, for example, by discoveries of alternative routes. Over a very long period, this book illustrates how the four main maritime passages have played a fundamental role, both economically and geopolitically, in regional and global affairs, and the strategic importance they have had over centuries. Each of the main parts of this book is devoted to one of the four major Middle Eastern waterways, divided into chapters and sections covering specific cases in a given time periods. In order to make the chapters clear and readily accessible, they are organized according to coherent chronological eras, starting with antiquity and ending with the present day.