Main article: 2011 military intervention in Libya

In March 2011, as forces loyal to Muammar Gaddafi advanced on rebels across Libya, calls for a no-fly zone came from around the world, including Europe, the Arab League, and a resolution[278] passed unanimously by the U.S. Senate.[279] In response to the unanimous passage of United Nations Security Council Resolution 1973 on March 17, Gaddafi—who had previously vowed to "show no mercy" to the rebels of Benghazi[280]—announced an immediate cessation of military activities,[281] yet reports came in that his forces continued shelling Misrata. The next day, on Obama's orders, the U.S. military took part in air strikes to destroy the Libyan government's air defense capabilities to protect civilians and enforce a no-fly-zone,[282] including the use of Tomahawk missiles, B-2 Spirits, and fighter jets.[283][284][285] Six days later, on March 25, by unanimous vote of all of its 28 members, NATO took over leadership of the effort, dubbed Operation Unified Protector.[286] Some Representatives[287] questioned whether Obama had the constitutional authority to order military action in addition to questioning its cost, structure and aftermath.[288][289]