The defection of Mousa Kousa, the foreign minister, on March 30th could have an important bearing on the chance of either of these first two scenarios. If the claim of the British foreign secretary, William Hague, that Mr Kousa is genuinely disaffected with the Qadhafi regime is correct, he could play a critical role in bringing the regime down, both by passing on information about its weak points and through engineering further defections. There is also the possibility that Mr Kousa is still acting for the regime, or parts of the regime. In this case his presence in London could mark the start of a negotiation about the regime's capitulation. His choice of London is not surprising, given his extensive contacts with the British intelligence and diplomatic services during the negotiations about lifting the sanctions imposed in the wake of the Lockerbie bombing and about dismantling Libya's nuclear weapons programme. As head of Libya's external intelligence services between 1994 and March 2009 (when he was made foreign minister), Mr Kousa was the chief Libyan interlocutor with the West over these issues.

The former foreign minister's defection is likely to encourage others, and by early April there were rumours that more senior officials were preparing to do the same. The decision by the US Treasury Department's Office of Foreign Assets Control (OFAC) to lift sanction against Mr Kousa on April 4th may encourage others considering absconding. In an official statement, OFAC said that Mr Kousa had "severed ties with the Qadhafi regime" and would therefore no longer be subject to an asset freeze. The statement explained that the aim of the sanctions "was to motivate individuals within the Qadhafi regime to make the right decision and disassociate themselves from Qadhafi and his government".

In the wake of Mr Kousa's apparent defection, the Qadhafi regime seems to have recognised the need to engage with the West and sent its envoy, Abdelati Obeidi, then deputy foreign minister, to Greece, Turkey and Malta to discuss possible solutions to the ongoing conflict. (Mr Obeidi was promoted to foreign minister on April 5th.) Meanwhile, a second envoy, Mohammed Ismail, who is a senior aide to Saif al-Islam Qadhafi, visited London. The diplomatic foray came amid growing speculation that Saif al-Islam and Saadi Qadhafi, the two more reform-minded of Colonel Qadhafi's sons, had proposed a plan for Saif al-Islam to assume power and oversee a transition to a more democratic system. The opposition has rejected this possibility outright.