The death of Osama bin Laden has driven the Libyan civil war from the headlines, but military operations continue—and the Western alliance must now begin to wrestle with some difficult questions.

An underlying premise of the "no fly zone" begun by a U.S.-British-French coalition and subsequently transferred to NATO control was that a resolute show of air power in Libya would enable rebel forces on the ground to rapidly take control of large portions of the country, while encouraging a supposedly restive population in Tripoli itself to take to the streets, emboldened by the sight of bombs falling on Muammar Qaddafi's headquarters.

Indeed, the defection of Musa Kusa, Qaddafi's former spy chief, seemed to bear out these predictions that the regime was under intense pressure and would soon collapse.

Things have not gone according to this plan, however, again demonstrating the limits of air power to bring about fundamental political changes. Moreover, Qaddafi's forces have adapted, no longer utilizing heavy weapons easily targetable from the air, in favor of using light, mobile, irregular units which are difficult to identify from high altitudes. Meanwhile, anti-Qaddafi forces were not able to take advantage of NATO airstrikes to effectively change the balance of power on the ground. And NATO is running out of targets which its air power can hit without raising the bar for civilian deaths.

Were it not for the bin Laden coverage, we would be seeing more pundits opining on how the Libya operation is not turning out as its partisans said it would, calling to mind another NATO operation a decade earlier—the Kosovo air war—another campaign which lasted weeks longer than expected and which also "ran out of targets".

NATO could still "get lucky"—an airstrike could succeed in decapitating the

Libyan regime—something which may have been intended with the raid that ended up killing Qaddafi's son Seif al-Arab last week. But if not, then one of the lessons from the Kosovo campaign is that leaders who are not prepared to live with an extended stalemate must eventually prepare for a ground war. President Barack Obama may have ruled out sending U.S. boots on the ground, but might he develop a new, intermediate category: "sneakers on the ground"—operatives, spotters, trainers, and advisers—some military, some civilian paramilitary—to create a capacity for intervention but without crossing the political third rail that is the deployment of "combat forces."

Only a last-minute diplomatic intervention caused Serbian leader Slobodan Milosevic to blink, averting the need for president Bill Clinton to have to commence ground operations in 1999. No such diplomatic deus ex machina appears on the horizon for Libya; the mediation efforts of the African Union to find a negotiated settlement failed because it did not lead to the immediate removal of Qaddafi from power.

And there are important differences with the Kosovo campaign that complicate matters. In 1999, the goal was to prevent Serbia from using its military power to crush a restive, separatist province; today, in Libya, the announced goal is not to protect and nurture a separate entity in eastern Libya but that of regime change—the removal of Qaddafi and his family from power over all of Libya. While Qaddafi's departure would be welcomed by the eastern part of the country, particularly in those areas centered around

Benghazi, the core regions that remain loyal to the existing government may have no desire to see the easterners come to power. When Qaddafi goes—because his regime has been dealt a mortal blow—will the West intervene to help impose the writ of the new government over all the country—and, having used humanitarian grounds as the basis for the UN resolution, stand aside if the new team decides to impose its rule by force? Or will the West have to assume the burden of peacekeeping and peacemaking responsibilities—a commitment that no NATO politician is willing to make openly, given the lack of enthusiasm for such a mission among the general publics of the alliance.

Another question is whether the alliance should begin targeting more of the infrastructure of Libya in order to put pressure on Qaddafi to capitulate. The logic of widening the target set in 1999 from Serbian units in Kosovo to targets across the country was a (misguided) belief that by imposing hardships on the Serbian population, they would rise up to overthrow Milosevic. This tactic backfired; Milosevic benefited from a renewed sense of nationalism to stay in power for another year and a half. In Libya, however, the alliance would want to encourage citizens in the loyalist regions not to support Qaddafi, and targeting them would seem to be counterproductive to that end. Moreover, the greater the destruction in the country, the more likely it would increase calls for the West to play a direct and significant role in the country's reconstruction.

A Milosevic-style capitulation ending the Libya operation does not appear to be in the cards. Nor does the West seem to have the strategic patience to let Qaddafi's regime wither on the vine (because it may still have sufficient wherewithal to crush the current rebellion). Plan B may have to be written up and executed after all.