The news of the day from Libya is that Colonel Qaddafi’s counterattack is succeeding, and it may be too late to help the rebels overthrow him. The neocon commentariat is preparing the ground to accuse Obama of losing Libya. Besides the hubristic assumption that American presidents are responsible for all the global misery they do not rush to prevent, the trouble with this argument is that the most popular means of U.S. military intervention, a no-fly zone, probably would not make much difference, whether imposed by Navy ships or aircraft.

Given the spectrum of ways that the United States can help Libya’s rebels, it’s odd that debate here centers on a no-fly zone, a form of military intervention that shows support for rebels without much helping them. No-fly zones commit us to winning wars but demonstrate our limited will to win them. That is why they are bad public policy.

No-fly zones are best suited to helping ground forces that can defend themselves against an opponent once we suppress its airpower. Northern Iraq in the 1990s is arguably a successful example. But they do little to overthrow entrenched leaders or help lightly-armed rebels defeat heavier forces. They do even less to protect civilians against armies or militias.

That distinction tends to be lost on proponents of no-fly zones. In 2008, presidential candidates Clinton, Obama, and Biden advocated a no-fly zone over Darfur, where warring militias victimized civilians far more than Sudan’s rusty aircraft. But the candidates were courting advocates of humanitarian intervention, not Darfurians, and didn’t need to bother with practicalities. They dropped the proposal once they had more power to implement it.

Libya is a better candidate for a no-fly zone, but not a good one. Fighter aircraft and helicopters supporting the portion of Libya’s military still loyal to Qaddafi are hurting the rebels. But the anti-Qaddafi forces also suffer a deficit of artillery, armor, and well-trained personnel, which a no-fly zone cannot remedy. As long as the forces now loyal to Qaddafi stay in his camp, he is likely to prevail or at least confine the insurrection to the east. (Director of National Intelligence James Clapper was foolish to give an honest assessment about the rebel’s prospects before Congress the other day, leading Senator Lindsay Graham to call for his firing and the White House to disown his comments).

A no-fly zone over Libya would likely give our pilots a front row view of Qaddafi’s victory and possible brutal attacks on civilians that supported rebellion. Having acted to prevent that, our leaders will then feel pressure to escalate to air attacks on Qaddafi’s troops or Tripoli, as Paul Pillar notes. The same applies had we implemented a no-fly zone last week.

If we care enough for the fate of the Libyan revolution to kill for it, we should take decisive action in its favor, such as using airpower to attack pro-Qaddafi forces. If we are rooting for the rebels to win but do not care enough to kill Libyans directly or risk our pilots' lives, we should limit ourselves to providing them with intelligence (intercepts and surveillance primarily), advice, and maybe arms while sanctioning the regime and jamming its communications. If other nations want to intervene, we should offer them like support, including transport to the fight. If we limit ourselves to those actions, we should do so in recognition of two risks. First, we may simply prolong a war and increase civilian suffering (The same goes for no-fly zones, as Doug Bandow wrote yesterday). Second, our efforts are likely to fail. We may soon be dealing with a regime we tried to overthrow, one that may return to its outlaw habits. If we are unwilling chance that, we should sit on our hands and admit that politics requires tough choices. I lean toward the second course.

What we should most avoid is confusing security and philanthropy. When leaders talk as if our intervention is protecting Americans but execute it as if they are doing charity work that merits little risk, they sow harmful confusion. Our potential allies may expect more than we are willing to give and take chances that they otherwise would not. The American public may come to support another dubious war based on threat exaggeration.

The leading example of this species of confusion is Anne Marie Slaughter’s op-ed in last Sunday’s New York Times arguing for a no-fly zone. Considering the complaint that we lack strong interests there, she argues:

Now we have a chance to support a real new beginning in the Muslim world — a new beginning of accountable governments that can provide services and opportunities for their citizens in ways that could dramatically decrease support for terrorist groups and violent extremism. It’s hard to imagine something more in our strategic interest.

Beyond the implausibility of the notion that a rebel victory in Libya will deliver that bounty, the trouble here is the mismatch of means and ends. If our interest in Libya is so large, why stop at a no-fly zone? Why not invade? Slaughter is either overstating the stakes or understating the means needed to succeed.

Maybe implementing a no-fly zone would demonstrate our commitment to oust Qaddafi, come what may, and thus cause greater defections among his loyalists or encourage him to bargain, as Slaughter hopes. That’s what political scientists call a costly signal. But because the other side’s stakes are life or death and the obvious attribute of a no-fly zone is its avoidance of costs, it’s unlikely to much change Qaddafi’s calculus.

For an argument in favor of U.S. intervention that avoids threat inflation, see Robert Pape’s latest op-ed.