The four American lives, including the first Ambassador killed since 1979 (Afghanistan), were sacrificed so that Obama could retain the election talking point that alQaeda was in decline ("Osama is dead and GM is alive"), and to avoid the Iran-Contra-style embarrassment of having the US population find out that Obama was supplying alQaeda with weapons to help oust Qaddafi and keep the Arab Spring rolling.
Probably worth the cost, to Democrats.
... into Syria...