Admiral Raoul Castex is Frances most important modern naval strategist. Military historian Eugenia Kiesling offers the essence of Castexs original five volume study, Théories Stratégiques, in a useful one-volume abridgment and a very readable translation. It emphasizes the admirals method of strategic analysis while omitting most of the historical narrative. Included are chapters defining strategy and relating it to policy and geography, analyzing the role of maritime forces and the significance of command at sea, prescribing a theory of conduct of operations, and introducing Castexs favorite themes: strategic manoeuvre, stratégie générale, and the theory of "perturbation." Two narrative chapters on German operations in the North Sea from 1914 to 1916 remain as examples of the authors historical style. The introduction places Castexs work in four distinct contexts: the international debate among naval theorists on the nature and importance of "command at sea," the controversy within France between advocates of the "historical" and "material" schools of naval strategy, the contemporary concern over coordinated naval strategy for total war, and his contribution to the formulation of French strategy between the world wars. In an era of expanding global responsibilities and shrinking national economies, Castexs balanced view of naval power offers many insights for todays new generation of naval thinkers.