This essay elaborates several basic propositions. First, the extraordinary changes in international communication and international transportation during the past 40 or 50 years have profoundly altered the horizons of business decisionmakers, giving enormous stimulus to the creation of multinational business enterprises. Second, in narrow economic terms the multinationalization of business activity has added to the efficiency of the world economy. Third, the advances in transportation and communication, reinforced by the existence of multinational business enterprises, have stimulated interaction between national economies and reduced the effectiveness of national controls, particularly in advanced countries. Finally, despite the increasing porosity of national boundaries these countries have been expanding and refining their national economic and social goals in ways that require more controls at national borders or more joint controls between cooperating states.