Leader becomes ever more reliant on his influential, bickering heirs who are rumoured to want a deal with the rebels
Mohammed Ismail, a key figure in Colonel Muammar Gaddafi's regime, has no portfolio and no job description.
An aide to Gaddafi's powerful son Saif al-Islam, the clues to his power are to be found in his office in Tripoli, a huge suite in a guarded compound. They are to be found too in what he has done: acting as an interlocutor for the regime on everything from blocked licences for arms sales and political contacts.
So the news that he has been in London in recent days for meetings with British officials is more than intriguing. Ismail is Saif's fixer – intelligent, discreet and powerful.
And increasingly, according to those familiar with how Saif and his brother Saadi are thinking, Gaddafi's sons have become aware that they have a problem that they need to find a way out of – despite Saif's bellicose language.
Ismail's visit, described in Tripoli as a trip to see his children who are being educated in Britain, is all the more significant given the defection of Libya's foreign minister and former external intelligence chief, Moussa Koussa.
He was here, say Foreign Office sources, on regime business. And that is significant at a time when diplomats and others have been in the capital to discuss how Libya might be after Gaddafi.
While it is difficult to assess in a regime as opaque as Libya, the evidence is that something is afoot. What it suggests is that under intense international pressure, key figures around Gaddafi – including, it would seem, some of his sons – are reaching out to channels of communication with the west.
And while there has clearly been an acceleration of contacts in recent days, some of which have led to defection as in Koussa's case, and others to the re-opening of a line of communication with Saif, what it says about the individuals involved and the stability of the regime is far more difficult to assess.
Sir Richard Dalton, a former British ambassador to Libya, cautions that part of the problem in working out the real centres of power within the Libyan regime – and how long it can survive – is rooted in how "non-apparent large parts of the state security apparatus are".
He said: "It is totally and utterly opaque. So much so it is incredibly difficult to interpret the lines of command. Then there is this mysterious entity called the old guard. I tried to avoid using it because it was so hard to say who they were."
Dalton believes that much power resides with individual members of the Gaddafi family – not least the sons – but how that power is exercised is both complex and nuanced.
Indeed, as the crisis has developed, US intelligence sources have suggested that Gaddafi has become ever more reliant on family and tribal ties, even pushing away old allies such as Koussa.
"The sons see themselves as heirs, modelled on Gulf princes.
"Without any concrete roles they get things done by getting on the telephone and making it happen. It is about patronage," Dalton said.
He believes the bickering sons' influence has increased since the former prime minister Shukri Ghanem was pushed into the background, allowing them more room to operate.
It is clear that the most visible of the sons, Saif and Saadi, have their own lines of communication and influence with the various state security organs, not all of whom are as easily biddable as they would like.
Saadi's camp too has let it be known that it believes the crisis has been badly handled, amid persistent rumours that Saif, Saadi and Mutasim – the son who is the national security chief – would prefer their father to relinquish real power and hand it to them, allowing them to negotiate a rapprochement with the rebels.
It is a desire that – judging by the rebels' attitude towards the Gaddafi family – may be wishful thinking at best, delusional at worst.
If the sons' power is circumscribed by their own internal family rivalries, by their mercurial father and by powerful state security officials, the power of another institution – the army – remains limited by distrust.
Since the rebellion against Gaddafi's rule began, that distrust has been shown not to be misplaced. Whole army units, particularly in the east of the country, have defected. There have been reported mutinies among soldiers ordered to attack the town of Misrata. As a consequence, officers have allegedly been placed under house arrest, and soldiers' cars entering Tripoli searched.
All of which leaves considerable power and influence in the hands of the state's two most prominent enforcers, Abu Zayd Umar Dorda, the director of Libya's external security service, and Abdullah al-Senussi, the chief of military intelligence.
Senussi was rumoured to have been killed after an equally rumoured abortive coup several weeks ago, but his name has since reappeared in several contexts that suggest he is still very much alive and influential behind the scenes.