What do you think NATO intervention in what they made into a civil war in Libya is about?

Obama said early on it was to stop Gadafi and that it would only last a short time, like a few days. We are now in day 91. Nato is 75% USA controlled and Obama must take responsibility for this war as he started it. He also went against the constitution because he did not ask for congressional approval.. Nato should get out NOW and Obama should be criticized sharply for starting a useless war. BTW, the USA gets very little oil from Libya, so saying it's about oil is just not true.