Muammer Gaddafi’s lethal repression of demonstrators in Libya is shocking, but not surprising – and may be one of the final acts of a desperate regime. The dictator has a long history of quashing the slightest sign of opposition. When UN sanctions were lifted in 2003, however, western powers showed casual disregard for Mr Gaddafi’s brutal domestic record in their rush to forge diplomatic and commercial links with the oil-rich country. Now, clashes between unarmed protesters and security forces have killed more than 200 people. A stark truth has been laid bare: a belligerent leader who transforms his foreign policy has changed nothing if he does not also reform his own country.

As elsewhere, the west prized an appearance of stability in Libya. The killing spree in Tripoli and other Libyan cities in recent days puts a lie to that. It is striking that the oil riches that bought Mr Gaddafi foreign friends failed to buy the peace of his own people – this is but one indication of how deep Libyan frustration runs at Mr Gaddafi’s 41-year iron rule. He has kept tribal leaders on a tight leash and retained a grip on defence, foreign affairs and security. Economic liberalisation has only highlighted what Libyans are missing out on. It is hard to know exactly what is happening while Libya keeps out reporters and maintains an internet blackout. But Mr Gaddafi has clearly drawn a tragic lesson from events in Tunisia and Egypt: that only swift repression may save him. When Seif al-Islam, the leader’s supposedly reformist son, addressed the country to calm unrest, he instead inflamed tension further by pledging to fight to “the last man standing”.

In both Tunisia and Egypt, the army proved critical in not turning its force on civilians, and maintaining peace once the autocrats were deposed: military leaders were able to separate their own fate from that of their leader. In Libya, the security forces are more of an unknown quantity and the army is not a coherent institution. The tribal nature of Libyan society adds a further layer of uncertainty.