there are many differences between libya and, say, iraq. one is that a rebellion was really underway at the moment we intervened. another was that a slaughter by the government was actually in progress. you know you get a different vibe if you were listening to someone like mo nabbous, pleading for help for his city ("are you just going to watch us die?") and his rebellion. nabbous was killed in gaddafi's initial assault on benghazi, which was prevented from total success by western intervention right at that moment. too late for mo. but not too late for so many others. listen to what his widow is saying, for example.
in iraq, rumsfeld or cheney just worked on a fantasy that we'd be greeted as liberators. here we don't have to fantasize. we can't control the entire unfolding situation. but we actually prevented a rebellion against gaddafi from being crushed and a city full of people, or several cities full of people, from being destroyed, right there, at that very moment.
that's why i'm not even going for the objections that run like: but obama didn't adequately consult with congress; we don't have a well-defined strategy or a clear statement of our goals; we don't have - for god's sake - an exit strategy. well you didn't have 24 more hours, much less 24 more years as these approaches seem to suggest. talking heads are objecting to the 'improvisational' nature of the operation. well, obviously. all these are just ways saying: yes, we're going to just watch you die.