An intergovernmental organization created in 1946 to control the rapid escalation of whaling. The original purpose of the IWC was to preserve whale stocks for commercial whalers. Whale populations, however, continued to decline, and in 1986 the IWC instituted a moratorium on commercial whaling that remains in effect. At the beginning of the 21st century, 40 countries belonged to the commission, but membership has fluctuated over the years. The commission's success has been limited by governments leaving the IWC, ignoring its policies, or breaching regulations