JOHN ERICKSON's The Soviet high command 1918-19411 is one of the most important works on the Soviet Union to appear in recent years. Unlike many detailed treatments of Soviet history, it contains a relatively summary coverage of the period of the Revolution and Civil War. The resulting conservation of energy is fully justified, for the military developments of the early period have been described in detail in the general histories of William H. Chamberlin and Edward Hallett Carr,2 as well as in numerous specialized works. A much larger portion of Erickson's book-nearly one-third-is devoted to the peacetime development of the Soviet military in the 1920's and early 1930's. Here, too, the broad implications of Red Army development, and particularly its relation to internal Soviet politics and foreign relations, have been extensively portrayed in general histories. Erickson makes a major contribution, however, in his exhaustive analysis (based on the huge body of captured German army documents in the possession of the British government) of relations between the Red Army and the Reichswehr. In all likelihood this section of Erickson's book will remain the definitive treatment of the subject. While most of his analysis adds illuminating detail to the familiar outline of clandestine German-Soviet relations, on some points he presents significant new conclusions. For example, he convincingly argues (p. 346) that the break in military relations soon after Hitler's accession to the German chancellorship, though due in part to the Reichswehr,