This is different than Reagan bombing Libya how? Well for one thing this is actually sanctioned by the UN.
Blowing up a air plane with Americans on board and dropping bombs on the nation that aided the terrorists who did so doesn't should never require our nation to go crawling to the UN to ask for their okay. In fact, fuck the UN because with the US doing the heavy lifting they'd be pretty much a useless and irrelevant organization.
Edit: Oh snaps !! I just realized something. Now that Libya is on the outs with the UN who is going to replace them as a leading member of the human rights commission (aka We hate the US and Israel brigade?) at the UN? Oh wait never mind the UN is a fucking joke. lol