This chapter evaluates thematically the fundamental values and structures shaping Second World War armed forces, their origins, their applications and their consequences, in the context of the combatants which defined the war's conduct. The USSR's armed forces followed a long-term path from mass toward energy. The Royal Navy's increasing and hard-won mastery of electronic war across the spectrum was decisive in its war against the U-boats. Sonar and radar, acoustic decoys and homing torpedoes, the list of gadgets and weapons is as long as the relationship between scientists and sailors is complex. The armed forces of the USSR were conceived and developed in the context of a comprehensive system functioning, domestically as well as internationally, on a Hobbesian basis of all against all. Weapons systems, operational doctrine, human dynamics all followed linear patterns of development, responding as much to the Soviet system's internal dynamics as to specific military contingencies.