The UN may just have authorised the third gulf war. I think the UN made the right call to stop Gaddafi using his air force against the opposition. If he re-established control over all of Libya, hundreds or even thousands of Libyans may have been executed.
But there is no guarantee this won’t happen anyway. It’s one thing to defend unarmed protesters, but a bit different when it is an effective civil war.
If the no fly zone is not effective, then pressure will go on, for more active intervention – and at that point you have a full war.
Gaddafi would lose that fight very quickly, but the aftermath could turn out to be more akin to Iraq than Egypt.