Speaking to a House Congressional committee, Secretary of Defense Robert Gates warned that a no-fly zone involves much more than simple air patrols to protect rebel forces.
"A no-fly zone begins with an attack on Libya to destroy the air defenses and then you can fly planes around the country and not worry about our guys being shot down," Gates said. "But that's the way it starts."
Gates also said that for for the operation to achieve the desired level of success it would require at least two aircraft carriers.
A successful first round of air strikes against anti-air defenses would also not preclude future strikes, nor would it ensure safety for American personnel. The danger would still exist of new air defense systems being built, requiring further strikes, and there is always the danger of shoulder mounted ground-to-air missiles and mobile anti-aircraft cannons being used against U.S. aircraft.
U.S. naval and air forces have recently been repositioned around Libya.