1. "No-fly zones" would kill Libyans
According to the head of US Central Command, General James Mattis, "You would have to remove the air defense capability in order to establish the no-fly zone so it -- no illusions here, it would be a military operation. It wouldn't simply be telling people not to fly airplanes." The intelligence film Stratfor goes into more details about what a "no fly zone" would actually entail:
2. "No-fly zones" would strengthen Gaddafi“It has been pointed out that a no-fly zone is not an antiseptic act. In order to protect the aircraft enforcing the no-fly zone, one must begin by suppressing enemy air defenses…Therefore a no-fly zone would begin with airstrikes on known air defense sites. But it would likely continue with sustained patrols by SEAD (suppression of enemy air defenses) aircraft armed with anti-radiation missiles poised to rapidly confront any subsequent threat that pops up. Keeping those aircraft on station for an extended period of time would be necessary, along with an unknown number of strikes. It is uncertain where the radars and missiles are located, and those airstrikes would not be without error. When search radars and especially targeting radars are turned on, the response must be instantaneous, while the radar is radiating (and therefore vulnerable) and before it can engage. That means there will be no opportunity to determine whether the sites are located in residential areas or close to public facilities such as schools or hospitals…Indeed, attacks on air defenses could cause substantial casualties, turning a humanitarian action into one of considerable consequence in both humanitarian and political terms."
The threat of foreign intervention is allowing Gaddafi to portray himself as an anti-colonial defender of Libya. While he continues to kill Libyans in practice, his rhetoric has shifted from attacking the resistance to attacking the West. As he stated recently,
This is of course pure hypocrisy from a tyrant who until two weeks ago was the darling of the West and who has sold the immense wealth of Libya to Western corporations. But Gaddafi is outnumbered and guns alone are not enough to defeat the resistance. He is desperate for an ideological assault on the revolution, and Western intervention gives him the perfect wedge to drive into the resistance in order to break its unity.
3. "No-fly zones" would undermine the Libyan revolution
Foreign intervention, ostensibly to prevent civil war, would in fact raise the threat of civil war by dividing Libyans on their attitudes to outside interference instead of uniting them in isolating and overthrowing Gaddafi's regime. The revolution has caused a split in the military, including pilots who deserted to Malta rather than bomb civilians. Generalizing this process--including international solidarity like the petition calling on the Maltese government to grant asylum to Libyan pilots--would create a true "no-fly zone".
Instead of a Libyan "no-fly zone" from below, the West is threatening a "US-fly zone" from above, which would undermine the confidence of pilots to resist and make them more likely to stay loyal to Gaddafi's call to defend Libya. The so-called "no-fly zone" would therefore undermine Libyans' own capacity to take over Gaddafi's army, while giving control of the country to his former supporters. Gaddafi and the West both want to crush the Libyan revolution, for slightly different reasons, and "no-fly zones" provide them both with a tool to do so.
4. "No-fly zones" would provide a cover for Western imperialism.
West has armed dictators across North Africa and the Middle East in order to secure control over the region's vast oil supply. But in two short months a revolutionary wave has already toppled Western-backed dictators in Tunisia and Egypt, while protests are building in Libya, Jordan, Algeria, Yemen, Bahrain, Iraq and Saudi Arabia. The West is desperate to stop this revolutionary process that threatens its control of the region, to whitewash its history in the region by presenting itself as a humanitarian, and to regain control.
There is also a new scramble for Africa, with the US trying to further militarize the continent with a command station in Africa, AFRICOM. "No-fly zones" would justify this imperial control of the region, and Libya is quite consciously being used as a first test case.
But the West is already bogged down in quagmires in Iraq and Afghanistan, and the economic crisis has heightened inter-imperial competition, so there is a debate amongst elites on how to proceed. The right-wing of the US establishment was first out of the gate in calling for intervention, with none other than Iraq War architect Paul Wolfowitz leading the charge. The US hardly gets any oil from Libya so intervention would give it greater access to the oil of its competitors while intimidating resistance movements in the region. But others in the administration are more cautious, realizing the exhorbitant costs of current occupations and the impact another Western intervention could have on what little stability remains in the region. In Europe the same splits that emerged during the Iraq War are once again evident, with Britain eagerly pressing for war (and already sending its own special forces, who were captured by the resistance), while Germany is hesitant and Russia opposed. Italy is one of the top importers of Libyan oil--and Berlusconi a close friend of Gaddafi--and was initially opposed, but as oil production is getting shut down anyways it would go along. China is competing with the US over African oil so it is also opposed, so without UN Security Council approval any intervention will be NATO (especially Britain and US) driven.
All this inter-imperialist rivalry goes to show that those leaders who are calling for, and would enfrorce, a "no-fly zone" are purely motivated by profit and their desire to access Libyan oil.
5. "No-fly zones" provide a cover for other Western wars
The other context is is the increasing opposition to the occupations of Palestine, Afghanistan, and Iraq. Where were calls for "no-fly zones" when Israel bombed Lebanon in 2006 or Gaza in 2008-2009? Where are calls for "no-fly zones" when NATO bombs civilians in Afghanistan, US drones kill civilians in Pakistan, or US Apache helicopters kill Iraqis? The US and Britain had "no-fly zones" in Iraq, which did nothing against Saddam Hussein but was part of a sanctions regime that killed a million people, and a prelude to war that killed another million people. "No-fly zones" are an act of war, and distract from other wars.
Canadian Peace Alliance states:
"The people of Tunisia, Egypt and Libya have done more to bring peace and democracy to their countries than years of US-led military occupations in Iraq and Afghanistan. The west needs to learn the lessons from those failed invasions and not compound the crisis in Libya."