First published in 1968 and 1976, the two volumes of this work still constitute the only authoritative study of the broad geo-political, economic and strategic factors behind the inter-war development of the Royal Navy and, to a great extent, that of its principal rival, the United States Navy. Roskill conceived the work as a peacetime equivalent of the official naval histories, filling the gap between the First World War volumes and his own study of the Navy in the Second. As such it is marked by the extensive use of British and American sources, from which Roskill extracted shrewd and balanced conclusions that have stood the test of time.