We face two questions. First, does the United States have a compelling interest in the removal of Gaddafi? Second, if we do, what are the most appropriate means? I believe that the answer as to interests is "yes." The public statements of President Obama, repeated daily by Secretary Clinton, that Gaddafi "must go," have staked America's credibility on the opposition's success -- a credibility made fragile by our letting expedient considerations trump our supposed commitment to democracy in the past. Great powers don't have the privilege of declaring a situation intolerable and then doing nothing to rectify it when they in fact have the power to do so. In addition, as others have pointed out, if our failure to act were to lead to a resurgent Gaddafi exacting a heavy toll in blood, it would send a chilling message to peoples across the region who are putting themselves at risk for the sake of dignity and a measure of freedom. Already, the Bahrain opposition has expressed its bitterness about Washington's siding with the Khalifa monarchy for the sake of its security ties with the Gulf states. Our current position in Bahrain is a close facsimile to that of the British from 1926 until their departure in the 1960s. They feared an Iranian challenge to their dominant political position, moved in to suppress a Shi'ite uprising, and did so due to strategic and economic interests in the Gulf region that it deemed of critical importance. The British installed Lord Belgrave as pro consul who ran the place for 30 years. A similar option does not appear to be open to us.
As to the legitimacy of an intervention, it would have to be approved by the United Nations Security Council under Chapter VII of the Charter. That means dealing with Russia and China, who have no enthusiasm for these ventures. A regional collective security body like the African Union may have some derivative authority to sanction an intervention. Unfortunately, its members right now are having a tough enough time holding onto downtown Mogadishu. Egypt is the exception in terms of military capabilities, but they are otherwise occupied.
As to the means, I defer to those better versed in these military matters. (Sanctions are but a symbolic gesture that could only harm the innocent.) One thought is worth noting. Any intervention that might entail the use of airpower runs into the extreme risk aversion that guides Pentagon thinking, as F.B. Ali points out. Focused attacks on critical military assets including ground troops might well be both necessary and could be decisive in themselves. But all recent experience tells us that the U.S. Air Force will not take to the air without prior suppression of all air defenses, communications centers and auxiliary facilities. Secretary Gates made that perfectly clear last week in pouring cold water on the more modest idea of an enforced "no fly zone" over Libya. Let's bear in mind that Mr. Obama is also an extremely risk-averse president. His cautious instincts are especially pronounced now that he is preoccupied with his re-election, which overshadows all policy decisions. Military action carrying possible consequences that he could not easily spin are seen as a mortal danger to his reelection hopes. So if he does agree to airstrikes in Libya, they are all the more likely to be of the massive kind that minimize chances of a losing a pilot or two. He should consider, though, the collateral physical and political damage that may ensue before committing himself to that course.