Even if many Libyans had not already been killed by coalition bombing (as they have been, according to Libyan television news), it is impossible to accept the claims of Western politicians to be concerned about Gaddafi's slaughter of 'his own people'. For one thing, Gaddafi has been brutally oppressing Libyan workers for decades: the 1996 prison massacre at Abu Salim is only the most egregious example. Moreover, the US, French and British states have been keen supporters of Gaddafi since the latter's pro-Western conversion in 2003, using Libya for the extraordinary rendition of potential 'terror suspects', who were tortured by Libyan intelligence operatives. And these Western states themselves never shown the slightest compunction about killing civilians (although they mostly have the decency to murder foreigners rather than 'their own'). Why, then, the sudden outpouring of humanitarian concern and moral outrage by Western politicians over the actions of a dictator who until recently they backed to the hilt?
The Marxist answer is a materialist one, of course: in view of the recent social unrest and Gaddafi's increasing political isolation locally and globally (Gaddafi had been making life rather difficult for foreign oil companies lately with high taxes and other demands), certain Western states are anxious to protect their vital trade in oil and arms with Libya, while furthering their geo-strategic aims in the region. Military intervention would also provide a valuable showcase for Western arms companies and governments eager to boost employment through 'military Keynesianism'.
Seeking to exert its influence in the region, France appears to have led the drive for a no-fly zone, closely followed by Britain. They must have ascertained that they could rely on the support of the US, which has now been dragged directly into the fray. Like Slobodan Milosevic or Saddam Hussein, Gaddafi has now outlived his usefulness to the US and can be disposed of. Compared to Iran and Syria, Libya is the weakest of the anti-US/Israeli states in the Middle East and therefore is a soft target for intervention, just as it was when Reagan attacked the country in the 1980s; if Libya had nuclear weapons, such intervention would be far less likely (for the same reason, don't expect an invasion of North Korea any time soon).
Ideologically speaking, the Libyan action also provides a highly convenient diversion for the beleaguered Western powers. For one thing, it diverts public attention from the growing domestic class struggle over savage cuts to jobs, wages, public services and pensions: if militarily successful (and there are good reasons to suppose that it will not be), the attack could produce a sort of twenty-first century Falklands Effect. It also diverts attention from the brutal repression - funded and supported by the Western powers - of the uprisings in other parts of North Africa and the Middle East. Hillary Clinton appears to have authorised the Saudis to help put down the pro-democracy protests in Bahrain, for example, in return for Arab League support for the attack on Libya.
Like the uprisings of what the capitalist media are calling the 'Arab spring', the imposition of a no-fly zone over Libya was unanticipated just a few months ago; but now that the game is afoot, the national bourgeoisies involved have everything to play for. This is not humanitarian intervention; it is a routine exercise in imperialist realpolitik.