The Libyan dictator is resisting the popular forces ranged against him in ways that his counterparts in Tunisia and Egypt did not. In Tunis and Cairo, Zine Abedine Ben-Ali and Hosni Mubarak were the faces of military regimes. Colonel Muammar Gaddafi is not the face: he is the regime. The Egyptian and Tunisian army chiefs calculated that sacrificing their nominal commanders-in-chief would preserve their own positions without jeopardising the interests of their American benefactors. Playing the role of saviours of the nation, after years in which the officer class enriched itself and ordinary soldiers were made to repress dissent, the armies in Tunisia and Egypt emerged as arbiters of whatever order will follow the post-dictator era.

Since Gaddafi seized power in Libya with his co-conspirator Major Abdul Salam Jalloud in 1969, he has remade the military in his own image to enforce his rule. In this, he enjoyed the successive support of the CIA, the Soviet Union and the East German security services. In Egypt, the army had some legitimacy from the Nasser era, when a whole generation of junior officers (all of whom entered the army after its officer class was expanded beyond the pashas in the 1930s) supported the revolution of 1952. When Nasser died in 1970 and Sadat was assassinated in 1981, the army set ground rules for transition that preserved its position. Libya, since Gaddafi overthrew King Idris, has never faced a transition. Gaddafi is not contemplating one, which leaves his army no option but to retain him. If he goes, they are finished.

Gaddafi has antagonised just about every segment of his population, as well as most of his fellow dictators in the Arab League. He has also earned the enmity of Islamic jihadists, who have suffered greater torments in his custody than their comrades in Guantanamo. Apart from Silvio Berlusconi in Italy, Gaddafi has no friends. Yet weapons stocks amassed from Russia, France, Britain and the US make sure that his unpopularity at home and abroad will not be enough to displace him. The Arab League took the initiative in demanding that his air force be kept out of the skies, even if it had to rely on Britain and France to bring about UN Security Council Resolution 1973.

The US defence secretary, Robert Gates, recently reminded a Congressional subcommittee that 'a no-fly zone begins with an attack on Libya to destroy the air defences.' It means a war, which Gates seems uncharacteristically opposed to waging. His caution was echoed by the German foreign minister, Guido Westerwelle, who said: 'The no-fly zone is not like putting traffic lights. It is an attack with bombs, missiles and weapons.' Germany abstained from Resolution 1973. Britain and France, which was selling more weapons to Gaddafi than any country apart from Russia until the insurrection began, are the main partisans of enforcing a no-fly zone. As American influence in the region appears to falter, because of its indecision at first in Tunisia and Egypt, its prevarication over Bahrain and Yemen, as well as its costly, losing wars in Iraq and Afghanistan, it seems that the old imperial powers are seeking to restore the position they held before the Americans undermined them at Suez in 1956.

Hillary Clinton has called on Arab states, particularly Libya's neighbours Egypt and Tunisia, to invade rather than let outsiders in. Egypt, however, seems less than willing. Its foreign ministry spokeswoman, Meha Bakhoum, answered Clinton with untypical bluntness: 'Egypt will not be among those Arab states. We will not be involved in any military intervention. No intervention period.'

While Gaddafi's forces slaughter Libyan rebels and promise to murder more, can the world stand by and do nothing? The world must acknowledge that the entire Middle East is in turmoil. Citizens have demonstrated for change in nearly every Arab country and in Iran. Some leaders will be expendable so long as the old order can survive with a new spokesman. In other countries, however, such as Iran and Saudi Arabia, the leaders themselves are the order. If international law requires equal treatment to all under universal standards, going to war for the Libyan people implies sending armed forces to protect Saudis, Iranians and others from the ruthlessness of their regimes. Are such interventions wise, or even possible? Will they lead to a fairer Arab world? Or will they mean that decisions are made by outside forces for ever?