the no fly and the assassination of Qadafi left Libya leaderless and with no real government institutions with the exception of the NOC
Elections were useless to unify and by 2014 the "2nd civil war" broke out which led to today's
chaos, unrest and failed 2 state government.
Libyan Civil War (2014–present)
https://en.wikipedia.org/wiki/Libyan_Civil_War_(2014–present)
In other words the vacuum of Qadafi's leadership led to militia rule ( both country/ citywide and neighborhoods) and with no real government ; Haftar and the Islamists went up against the 'transitional' government in Tripoli.
Haftar broke out Parliament, and shipped it to Tobruk/Bengazi and claimed he was the legit government.
Libya Dawn and the Islamists set up a rival governments in Tripoli -the "General National Congress". (GNC)
So if you think "what was the proximate cause of today's failed state of Libya" -
it all goes back to killing Qadafi/regime change.
NATO was responsible for that -so NATO is the proximate cause of todays' Libya
That's what happens in every civil war.. Gaddafi was so afraid of the Libyan people that his military and police were all African mercenaries. The US had no way to keep him in power ..