The honest truth of the matter is that the USA - and the rest of the world - had to intervene. It seemed extremely likely, indeed almost certain, that Gadaffi was going to commit one of the most awful massacres of the last few decades should he have taken Benghazi. To simply stand by and let it happen would not be acceptable. The international community had basically done that with the Srebrenica massacre. For the politicians in charge (Obama in the case of the US) it was both morally and politcally the only course of action.
Simply put, this is not Iraq. This action has immediately saved lives in the tens, possibly hundreds of thousands. For the international community not to have done these actions would be to essentially give approval to these atrocities.
