ONE of the more perplexing problems facing the United States in the twentieth century has been that of selecting fairly which citizens shall serve in the armed forces. Today controversy surrounds the application of the Selective Service System to them raising of troops for the Vietnam War. Thus far, however, the hostilities in Vietnam have not posed one difficulty for the Selective Service System that existed during World War II, namely, the necessity of granting substantial numbers of industrial and occupational deferments, except insofar as educational deferments are a form of industrial ones. Such deferments have grown more important during the world wars of the twentieth century as nations engaged in full-scale hostilities have been forced to rely heavily on them in order to maintain the industrial and economic strength of the nation.