The war changed this. By nineteen nineteen, Americans had almost three thousand million dollars more invested in other countries than foreign citizens had invested in the United States. American foreign investments continued to increase greatly during the nineteen twenties. Increased foreign investment was not the only sign of growing American economic power. By the end of World War One, the United States produced more goods and services than any other nation, both in total and per person. Americans had more steel, food, cloth, and coal than even the richest foreign nations. By nineteen twenty, the United States national income was greater than the combined incomes of Britain, France, Germany, Japan, Canada, and seventeen smaller countries. Quite simply, the United States had become the world's greatest economic power. America's economic strength influenced its policies toward Europe during the nineteen twenties