The IMF was created at the end of World War II to help regulate the international economy. Its main purpose is to ensure that national economic policies do not restrict or inhibit the international flow of commodities and payments as they did, so disastrously, in the 1930s. By requiring members to subscribe to a common set of rules regarding exchange and payments arrangements, the Fund attempts to prevent the narrow pursuit of national interests from impeding international growth and stability. The need for an institution to play this role stems from the fact that while capital and trade have become increasingly internationalized, economic policy continues to be formulated essentially by individual nation states whose interests often do not coincide.