French military historical writing is notoriously of a high order. Captain Laurens' book on submarine warfare is quite up to the standard set by tradition, and is apt to be for some time the accepted treatment of the subject. The author, who is now chief of the historical section of the French Naval Staff, was during the last years of the war chief of submarine intelligence, and is well known for his other writings on naval aspects of the great conflict. In this volume he is not content with a narrative of submarine operations. On the contrary, he takes up the whole story of the origins of the German submarine campaign, discusses the political aspects of the problem and its effects on international relations, to say nothing of the economic side of the struggle. The book is based not only upon a complete command of the published material, especially German, but also upon the papers of the historical section of the French navy. In other words, it is well informed and authoritative, as well as being thoroughly readable. Captain Laurens is to be congratulated on producing an excellent and impartial account of a crucial problem. It is only to be regretted that he has seen fit to omit specific references to his source material and that he has not given at least a brief working bibliography of the subject.