IT is not only geographically that the United States is now a Pacific country. Politically, economically and historically as well its polarization is toward the Pacific. The evidence is plain. Theoretical substantiation is unnecessary. The Stimson Doctrine, the refusal of naval parity to Japan and the massing of the fleet in Pacific waters all signify clearly enough that the Far East is destined to bear the impress of the American nation. What pattern will the impress take? To answer this question it is necessary to consider the internal social composition of the American nation. An analysis of American society is more than an exercise for graduate students in the social sciences. It involves the determinants of America's role in the Pacific area no less than those of America's internal social evolution. What are the lines of social grouping in the United States? What are the relations between social groups? Where does power of decision lie, and where are the mainsprings of American action to be sought? The questions are more easily put than answered. Always confused and out of balance, the social composition of the United States has never been more confused than now. The key to the understanding of America has always been the lack of class fixity; not as a result of any philosophy of democracy, but rather as the result of a continental expanse of rich and undeveloped territory and a time of technical and material progress. No class lines could remain fixed in a continent abounding in opportunities for the energetic and enterprising. The log-cabin-to-millionaire-palace saga, while generally romanticized, also had a factual basis. The nineteenth century was a time of class mobility everywhere. In the United States it was nothing less than fluid. For this reason more than any other the radical and revolutionary ideologies originating in Europe, out of European social conditions, fell on deaf ears in America. They were not relevant. They were stated in an alien social language.