Justin Logan at Cato makes a good point answering the interventionist logic. If the goal is to remove Qaddafi, then logic says remove him -- send in the necessary military forces and overthrow him. But this won't fly in public and international opinion, so the interventionists are proposing a half-measure that I suppose is an incremental process of getting rid of Qaddafi, but this creates doubts about the plan, Why pretend we are only creating a no-fly zone, which if we create committs us to deal with any military response from Qaddafi? This is how we get bogged down in between victory and defeat. We don't want to admit defeat, but we want to do what's necessary to accomplish our mission, so we flail and bog down in the mud hole.
Plus, we don't know what forces are fighting for control. It's a complex problem, and I certainly don't want to see innocent people slaughtered, but why does America have to be involved when there are countries closer in the region with national interests at stake? There has to be a point where America backs off and says "No more", especially in the Middle East and Northern Africa.