I would remind David that the socialist opposition to imperialist intervention against Germany after the rape of Belgium or, for that matter, of independent socialists in the West to arming the Hungarian rebels in 1956 had nothing to do with the issues raised by those opposed to "humanitarian interventions." Of course "humanitarian interventions" is transparent nonsense. You are just reinventing the wheel. Socialist resisted intervention in Belgium because they recognized it as a fig leaf to grab Germany's imperial possessions and to strangle Austria and Turkey. In the case of Hungary in 1956, ---which posed a greater challenge---it was only reluctantly resisted for fear of triggering a third world war. But the fist line of evaluating our attitude towards an imperialist intervention is whether it would strangle the autonomy of the democratic movement that it claims aid and subordinate that movement to the interests of imperialism. The "liberation" of Kuwait was a complete imperialist lash up and had nothing whatsoever to do with strengthening the forces of democracy. And that's the point. Once the question of subordination and neutralization of native democratic forces has been addressed, then the question of imperialism's wider prospects for stifling democracy are put on the table.
I would further remind David that independent socialists---a tradition, I believe that he once associated himself with--actually urged the nationalist democratic movements of occupied Hitlerite Europe "not (to) hesitate to come to practical agreements with Allied imperialism, or its agents or its representatives, by which they are provided with material aid and supplies for the struggle. That means, furthermore,that the line of policy advocated by the revolutionists in these movements includes the advice to take all the arms that may be put at their disposal, in the event of an invasion of that continent by the Allied armies". Was this the wrong thing to do? Should they have read them the riot act about democratic imperialism's real aims? Or could arming nationalist democrats have had further implications down the road, as socialists believed, for challenging capitalism or at least strengthening democracy?
The Libyan rebels had two choices (not mutually exclusive, to be sure) with respect to their demands on imperialism. They could have demanded that Qaddafy's frozen assets be turned over to them so they could purchase guns, antiaircraft missles etc. But that would have given the West a decisive hand in choosing the most compliant elements among the rebels to empower, both with money and arms. Or they could have asked---as they have---for air cover to level the terms of war. I think this option leaves them the greatest autonomy. The decision probably was made on the basis of urgency rather than political calculation. But either way, the decisive question--I think--for socialists is whether the insurgency has been coopted by the intervention.
As far as aircover itself, I see no principled difference between the demand for arms and the demand for air support. Both are demands for active imperialist intervention. So I put the question back to you, David. Why would you support one, but virulently oppose the other? Is it tactic or principle?