The lack of free trade was considered by many as a principal cause of the depression causing stagnation and inflation. Only during World War II did the recession end in the United States. Also during the war, in 1944, 44 countries signed the Bretton Woods Agreement, intended to prevent national trade barriers, to avoid depressions. It set up rules and institutions to regulate the international political economy: the International Monetary Fund and the International Bank for Reconstruction and Development (later divided into the World Bank and Bank for International Settlements). These organizations became operational in 1946 after enough countries ratified the agreement. In 1947, 23 countries agreed to the General Agreement on Tariffs and Trade to promote free trade.