Although it is not acknowledged, it is hard to credit any other outcome as the ultimate objective of the U.N. Security Council resolution to authorize "all necessary steps" to protect civilians, and of the beginning of military activities by a coalition, led by France, the U.S., and the U.K., to establish a "no-fly zone" for Qadhafi's air force over Libya.
The actions were defensible and just barely in time to prevent the routing of the rebel forces from their stronghold in Benghazi and a massacre which surely would have followed. Perhaps, not even in time: the immediate response of the Qadhafi regime to the U.N. resolution was to declare a cease-fire, a ruse designed to give his forces time to invest Benghazi in a siege.
It is likely that the initiation of air attacks on Qadhafi's forces may give the rebels a chance to regroup and protect some of their strongholds, maybe even to re-emerge in some of the Western Libyan towns from which they had been brutally driven. It does not seem likely to achieve either a negotiated peace or a comprehensive defeat of Qadhafi forces.
It still falls on the rebels to do most of the work if the country is to be freed of Qadhafi's rule by force of arms, and, barring a new round of defections by loyalist forces, unclear whether they will have the capacity to do so. It is extremely important that the US keep to its pledge not to involve any ground forces (except possibly for rescue operations if any of our planes are shot down); the American public will not support a new, third ground war in a Muslim country, one which has little connection with Al-Qaeda or its allied movements (as with Iraq's Saddam, Libya's Qadhafi and Al-Qaeda have been sworn enemies), and from which the oil production, though significant, is not critical. There are too many parallels with Iraq--both the first and second conflicts there--to feel very comfortable with the initiation of foreign involvement in the hostilities. They include the very vexing problem of what would be done, if there were some sort of national liberation, with Qadhafi's minority of tribal supporters, who are not going to accept defeat and loss of privilege with good grace.
I do support the limited aims announced and intended from the short-term actions, but if reducing civilian casualties is indeed the goal, a standoff and prolonged civil conflict are not going to achieve it. Reducing the degree of intensity of conflict may be achievable in a week or so, then we might redouble our efforts (which I hope have started) to induce some of Qadhafi's protectors to turn on him and kill him in his sleep--followed by a 24-hour notice to his sons to get out of Dodge. This remains the best outcome for this challenging, somewhat ill-considered rebellion.