American capital was the main sustainer of the international economic system during the 1920s. The role of American financial resources has sometimes been referred to as the diplomacy of the dollar. In some such fashion, a revitalized global economy came to hinge on a relationship of financial interdependence between the United States and Europe, and indeed the rest of the world as well. The penetration of world markets by American goods as well as capital and technology was providing a basis, the economic foundation, for the postwar international order. If American economic influence was linking different parts of the world closer together, thereby creating a greater sense of global interdependence, there was a contrary trend as well: the new immigration policy of the United States. Both the 1921 and the 1924 immigration laws established a quota system on the basis of nationality.