There was no UN mandate to wage war on Libya. There was a resolution to enforce a no-fly zone, that's it. [link]
Obama didn't seek congressional approval either. The war the US-led NATO forces waged on Libya was illegal & unconstitutional.
Arming jihadis & sending in black ops teams, looting Gaddafi's gold & weapons & shipping the weapons to Syria to rinse & repeat was all done under Obama's watch & with his explicit approval.
Do people really care that this asshole said nice things about immigrants?