Variations on a familiar theme-and a valid one-that the U.S.S.R. is a global power in one dimension, the military, and falls short in others. Paul Dibb is an Australian scholar well versed in the Soviet Union and the Pacific area. His assessment of Soviet strengths and weaknesses is based on a wealth of evidence: he looks at economic, security and other questions primarily as they appear to Moscow, takes account of the interpretations of others, and pictures a superpower with enormous problems that spell decline but not necessarily disaster.