Marine Corps General James Mattis, commander of the US Central Command, appears before the Senate Armed Services Committee on Capitol Hill in Washington DC, March 1, 2011. Enforcing a no-fly zone over Libya would first require a military operation to destroy the north African nation's air defense systems, top US commander General James Mattis warned Tuesday. A no-fly zone would require removing "the air defense capability first," Mattis told a Senate hearing. "It would be a military operation," he added. AFP PHOTO/ Chris KLEPONIS (Photo credit should read CHRIS KLEPONIS/AFP/Getty Images)