Who bears the responsibility for the upcoming Benghazi bloodbath?

Should the US and Britain and or NATO just go it alone without waiting for a UN go ahead? Saudi can march down to Bahrain and shoot protesters, but can't enforce a Libya no-fly zone? The UN hand wringers let this happen? We said 'Never again' after Sarajevo AND after Rwanda AND after Southern Sudan. Now it's going to happen again isn't it, Mr Ban.