Intervening in Libya was a big mistake, but I think it's way too simplistic to just pin all the blame on Obama. Most of the impetus for this mission came from Europe, which reading the posts on this forum also makes clear. Of course Obama should have pulled a Chirac and told France and UK to go it alone.
Of course, why would we bother saving all those lives if it takes so much time and make us waste so much money ? 
Maybe I'm hallucinating, but it doesn't appear to me that mass killings and violence have stopped when the no-fly zone was put into effect. It also isn't going to win any more Arab friends.
Let's remember that having the approval of the Arab League doesn't translate into approval from the Arab people.
