The no-fly zone over Libya authorized by last Thursday's U.N. Security Council resolution is the latest established by Western nations in the past two decades.
After the Gulf War ended in 1991, no-fly zones were put in place over both northern and southern Iraq by the United States, Britain and France.
The northern no-fly zone was part of "Operation Provide Comfort," designed to protect the country's Kurdish minority. "Operation Southern Watch" was imposed to protect Shi'ite Muslims. Both no-fly zones remained in effect until the U.S.-led invasion of Iraq in 2003.
In 1993, NATO began enforcement of a United Nations-imposed no-fly zone over Bosnia. "Operation Deny Flight" was later expanded to include providing close air support to U.N. forces on the ground.
The no-fly zone over Libya is intended to prevent government forces loyal to Libyan leader Moammar Gadhafi from carrying out air attacks on rebel forces. It follows an appeal by the Arab League on March 12 that a zone be established.
U.N. Resolution 1973 that put the no-fly zone in place was approved by a vote of ten to none in the 15 member Security Council. The five abstentions were China, Russia, India, Brazil and Germany.