Although White House and European leaders have repeatedly threatened to establish a no-fly zone over Libya, such a complex operation could require hundreds of aircraft and a bombing campaign to neutralize the country's air defense system, current and retired U.S. military officers say.
Libya's military is considered no match for those of the U.S. and its allies, but it would take a large-scale Western effort to establish round-the-clock patrols over Libyan airspace to deter further attacks on rebels, the U.S. officers said.
"This is all doable," retired Air Force Lt. Gen. Michael M. Dunn, former vice director for strategic plans and policy for the Pentagon's Joint Staff, said of creating a no-fly zone.
But "the simple fact of the matter is that it's not simple," he said.
There is little evidence that consideration of a no-fly zone has moved beyond the conceptual stage in Washington or in European capitals, where officials seem to be hoping, at least for now, that the threat alone will deter the Libyan air force from attacking protesters.
British Prime Minister David Cameron said Monday that he had ordered his military to begin planning for such an operation. The White House said a no-fly zone was under "active consideration."
But a senior administration official said the option would be chosen only in a narrow circumstance: if Moammar Kadafi ordered large-scale air attacks against fellow Libyans.
"If Kadafi begins an all-out assault on the opposition, creates a humanitarian crisis, and it includes significant use of air power, then that would be the kind of compelling situation that spurs the international community to take that step," said the official, who spoke on condition of anonymity because of the sensitive nature of the discussions.
If a no-fly zone is implemented, one of the biggest worries for U.S. planners will be Libya's surface-to-air missile batteries along its coastline, especially its so-called SA-6 missiles, which, though designed years ago by the Soviet Union, remain able to shoot down U.S. and European fighters, several analysts said.
Libya is believed to have about 50 SA-6 missiles, which are easy to move to avoid detection. Pentagon planners probably would seek to neutralize the SA-6s by warning Libya's military not to target NATO aircraft but also with airstrikes against batteries that took threatening actions, such as activating their radar, the officers said.
The possibility of the North Atlantic Treaty Organization engaging in combat has been little mentioned amid the discussion of a no-fly zone, but U.S. officers said that suppressing an opponent's air defense system is a basic tenet of American Air Force doctrine.
When the U.S. instituted a no-fly zone over southern Iraq in the 1990s, the Air Force attacked the Iraqi air defense system so relentlessly that its radars rarely were turned on, allowing U.S. and allied fighters to patrol without suffering any combat losses for more than a decade.
In the initial stages of a no-fly zone over Libya, air defense batteries might test NATO pilots. With Kadafi and his supporters desperately clinging to power, there is also the possibility that at least some Libyan fighters would attempt to engage NATO aircraft, several officers said. The Libyan air force flies Vietnam-era, Soviet-designed MIG fighters that are not considered much of a threat to U.S. aircraft.
Even so, retired Air Force Lt. Gen. David A. Deptula said, "If you are going to do this, you have to be prepared for the possibility that aircraft are going to be engaged in combat."
To carry out patrols over Libyan airspace 24 hours a day, the U.S and its allies would need hundreds of aircraft, including fighters and refueling tankers, Dunn said. The U.S. could reduce the number of aircraft required by flying only during the day, when attacks on anti-government rebels are most likely, or by going after only Libyan airplanes, not helicopters, he said.
Moving hundreds of aircraft to air bases around Libya would take several weeks, but it could be done without too much effect on U.S. combat operations in Afghanistan. It would not be possible to sustain a no-fly zone using fighters flying from U.S. aircraft carriers, Dunn said.
Before the U.S. and its allies could begin positioning aircraft, they would need consent from governments in countries near Libya to use bases, a hurdle that at a minimum would require winning U.N. authorization for the operation, as well as an endorsement from NATO.
To minimize flight times to Libya, it would be vital to have access to air bases in southern Italy, including a large installation in Naples, and the U.S. might also seek permission from Greece, Egypt or Tunisia, Dunn said.
Italy would look at allowing bases in the Mediterranean to be used by allies only if the operation was authorized by the United Nations, Foreign Minister Franco Frattini said Monday.
Times staff writer Paul Richter in Washington contributed to this report.