Back in Jan. '09 I blogged about an article that discussed the notion of 'demonstrative compellence' (as the author termed it) in connection with the G.W. Bush policy toward Iraq. The argument in a nutshell was that the invasion of Iraq was meant to signal to Iran and N. Korea that if they didn't straighten up and fly right they might be next. The strategy was, in essence, a complete failure, at least with respect to its intended targets. Iran continued its less-than-transparent nuclear program and N. Korea showed, on occasion, some apparent willingness to negotiate but basically continued on its path toward acquiring nuclear weapons.
Why bring this up now? Because some might think, not unreasonably, that one motive for the NATO intervention in Libya was to send a signal to possible emulators of Gaddafi that they had better not contemplate atrocities. The trouble is that the signal, if one was intended, has had little effect: the Assad regime in Syria has killed lots of protesters (though recent events in Syria, with some soldiers perhaps having mutinied and killed other members of the security forces -- it's still not entirely clear what happened -- point to the possibility of a split in the armed forces); the Saleh regime in Yemen killed lots of civilians before Saleh's departure; and the Bahraini regime used violence against protesters before (and after) calling in Saudi troops to shore itself up.
The case for the NATO intervention in Libya thus has to be made mostly on humanitarian grounds and in terms of Libya alone, it would seem, since from the standpoint of demonstrative compellence it's been a washout.