Also based on experience of inter-war years, U.S. planners developed a concept of economic security—that a liberal international economic system would enhance the possibilities of postwar peace. One of those who saw such a security link was Cordell Hull, the United States Secretary of State from 1933 to 1944.[Notes 1] Hull believed that the fundamental causes of the two world wars lay in economic discrimination and trade warfare. Specifically, he had in mind the trade and exchange controls (bilateral arrangements) [2] of Nazi Germany and the imperial preference system practiced by Britain, by which members or former members of the British Empire were accorded special trade status, itself provoked by German, French, and American protectionist policies. Hull argued
[U]nhampered trade dovetailed with peace; high tariffs, trade barriers, and unfair economic competition, with war…if we could get a freer flow of trade…freer in the sense of fewer discriminations and obstructions…so that one country would not be deadly jealous of another and the living standards of all countries might rise, thereby eliminating the economic dissatisfaction that breeds war, we might have a reasonable chance of lasting peace.