The hearing in Washington, and the further details it provides about the security problems in Benghazi, is just the latest revelation of the intelligence failures which contributed to the murders of American ambassador Christopher Stevens and three members of his team.

The US media has charted how the Obama administration has changed its posture half dozen times since the killings. When The Independent broke the news that there was evidence to suggest that the storming of the consulate was not because of spontaneous anger over a film about the Prophet Mohammed, but a pre-planned plot, there were denials from the State Department.

The State Department also denied that there had been warnings in the past about the deteriorating situation in the Libyan city. The stance begun to crumble within days with American and Libyan officials, including the interim President, Mohammed el-Megarif, lining up to contradict the account from Washington and pointing out how information had been available about extremist groups plotting to carry out an attack.

US officials spoke of the need to keep a lid on the scandal before November to prevent Mitt Romney from using it as an electoral weapon. However the pressure generated by congressmen and senators, leaks by dis-gruntled officials and continuing accounts of journalists made that position increasingly untenable.

Ironically, what unfolded in Benghazi was a vindication of the West's support for the Libyan revolution. While crowds were attacking US and European embassies elsewhere, people in Benghazi were also out in the streets – to drive out hardline groups, in particular Ansar Al-Sharia, which had played a role in the killings of Stevens and the others. Chris Stevens was not without doubts about post-Gaddafi Libya. He was, however, firmly of the belief that Western engagement was essential to balance that of reactionary Islam, what happened in Benghazi after his death was a poignant vindication of that view.