The more Haftar is legitimized, the less accountable he is, and the less he can be trusted.
The group has held the city since June 2015, implementing its brutal brand of Sharia law.
Amid the celebrations in Derna, schools are reopening and people are returning to work.
Top Libyan commander says that the group "exploited a security vacuum."
Sameh Shoukry says stability in the country "primarily will have to be dealt with by Libyans."
Washington is "watching the situation very carefully" but no decisions have been made.
The group have publicly crucified a family in Libyan town ahead of the forced pledge, according to sources.
As jihadis use cultural vandalism as a weapon of war, fears are increasing for the country's Greco-Roman heritage.