Pundits who, in the wake of the Tunisian and Egyptian revolutions, extolled the power and virtue of non-violence, have been brought up short by the events of recent days in Libya. The regime of Colonel Gaddafi, in power since 1969, is engaged in a violent life-or-death struggle with its own people, and so far it’s hard to say which side has had the worst of it.

If Egypt and Tunisia echoed the peaceful transformation of 1989 in East Germany and Czechoslovakia, then Libya is Romania: a violent confrontation whose outcome will ultimately depend on the loyalty of the armed forces.

There’s no doubt Gaddafi is in big trouble. He appears to have lost control of most of the eastern half of the country, and there has been fighting in the capital, Tripoli, with reports of government aircraft bombing civilian targets. World leaders have issued strong if ineffectual condemnations.

Gaddafi’s only appearance this morning has been a 20-second televised speech in which he assured people that he was in Tripoli and not, as had been reported, a fugitive in Venezuela. (“Do not believe these channels they are dogs.”) Hardly enough to inspire confidence.

Most striking has been the mass defection of much of Libya’s diplomatic corps: its whole delegation to the United Nations denounced Gaddafi and called for international intervention, and a number of senior ambassadors — including those to China, India and the Arab League — have resigned in protest. The justice minister did the same, and Gaddafi’s senior aide appeared on Al Jazeera to support the rebels. I can’t recall a government that has survived after this sort of high-level desertion.

All the same, the key to the situation is the attitude of the Libyan military. Unconfirmed reports suggest that a number of officers have gone over to the rebels, but so far there is no sign of the sort of disloyalty from senior generals that will be necessary if Gaddafi is to share the fate of Nicolae Ceauşescu.

It’s easy to think of revolutions as popular outbreaks that sweep away a regime in its entirety and replace it with leaders drawn from the streets. The reality is almost always different: governments fall when significant parts of the establishment switch sides and throw in their lot with the people, and those establishment figures often take prominent places in the first post-revolutionary governments.

Dictators don’t drive the tanks or fire the guns on their own; they depend on subordinates to do their bidding. And when those officials and ministers and diplomats and officers and ordinary soldiers realise that the game is up, or simply sicken of the bloodshed, they cease to be reliable instruments of tyranny.

A lot of the talk in the last few days has been not of 1989 but of 1848, when liberal revolutions in Europe achieved short-term success but ultimately failed to overthrow the most reactionary regimes. Like Deng Xiaoping in 1989, the rulers held their nerve, made temporary concessions and let the masses control the streets for weeks or even months, but kept the army loyal and eventually used it to crush the rebels.

Bismarck’s verdict on that “year of revolutions” still haunts us:

“The great questions of the day will not be settled by speeches and majority decisions – that was the great mistake of 1848 and 1849 – but by iron and blood.”

Iron and blood rule Libya for now, but for how much longer? A Libyan called Otman, writing to the BBC from Tripoli overnight, expressed the ominous truth:

“We, the Libyan people, are in the deep end. We either sink or swim; we either topple the regime or face being massacred. We have no choice … we have to keep moving forward, there is no going back.”