Through much of his bloody history, Colonel Moammar Gadhafi has played tribes against each other, even instigating small tribal wars within his own borders as a way of punishing rebels.
Now, the rivalries he has unleashed within Libyan society have resulted in a worrying pattern in the growing conflict: tribes that supplied significant manpower to the elite security forces have proven reluctant to join the revolution, and several towns dominated by those tribes remain controlled by Col. Gadhafi. As rebel forces advance, they risk transforming their uprising into a war between large groups of Libyans.
"I'm really afraid of this," said Khalil Ali Al-Musmari, a retired professor of anthropology and sociology in the rebel stronghold of Benghazi. "We should not be tribes in this revolution. It's better to say this is the peoples' revolution, not the tribes', because that could create dissent among the tribes."
Like many others here, Mr. Al-Musmari said the foreign media have often crudely misrepresented the nature of tribal power in the country, by talking about tribal leaders as though they still commanded the same obedience they did in ancient times. Unlike the tribesmen from less-developed countries, he said, the educated Libyans in coastal cities make their own political decisions and do not feel obligated to follow their tribal elders. The revolution has split some major tribes, as loyalists fight their own blood relatives among the rebels.
But in the desert outposts where skirmishing threatens to evolve into a full-blown civil war, tribes remain a factor for Libyans when selecting a wife or a business partner - and the tribes now seem to play an important role as rural villagers decide who to fight.
"Gadhafi sowed dissention and hostility among the tribes," said Mohammed Omar Mukhtar, the 90-year-old leader of the Imnifa tribe. "He relies mainly on three tribes, although many people from those three are not loyal to him."
Mr. Mukhtar said that three major groups - the Warfalla, Tarhunah, and Migarha - supplied many of the recruits for Col. Gadhafi's most loyal security forces. The dictator's own namesake tribe, the Qadhadfa, is relatively small, so he frequently relied on young men from the other three tribes in the desert towns hundreds of kilometres south of Tripoli. Those remote towns, such as Sabha, have emerged as crucial enclaves of support for the regime and staging grounds for attacks on revolutionary forces.
The elderly tribal leader hastened to point out that members of those three tribes are also represented among the leaders of the revolution, and many have disavowed any links with Col. Gadhafi. The retired professor emphasized similar points, making it clear that talk of tribal divisions in the country is dangerous.
"Now, all the journalists are asking if the Warfalla tribe will join the regime or the revolution. But the answer is: both," Mr. Al-Musmari said.
If the tribal system creates a threat of broader war in Libya, it also holds out the prospect of peaceful solutions. Mr. Mukhtar's father, Omar Mukhtar, became a revered national hero - nicknamed "Lion of the Desert" - for uniting the tribes against colonial occupation by forces under Benito Mussolini. (The actor Anthony Quinn played Mr. Mukhtar in the movie version.) The hero's son says he still believes the tribes will come together again, in resistance to Col. Gadhafi, with patient negotiations among tribal leaders.
Even as rebel forces continue battling west along the main coastal highway toward the Gadhafi stronghold of Surt, Mr. Mukhtar said that rebel leaders in Benghazi are reaching out to the city's tribal leaders. A large group of Qadhadfa tribesmen are concentrated west of the city and remain mostly loyal to the regime, but some rebels are hoping that the other major tribes in the city, Firjan and Miadan, can be persuaded to join the revolt.
"We want to take Surt peacefully; it's ongoing," Mr. Mukhtar said, declining to elaborate.
It can be hard for outsiders to gauge the influence of tribal elders such as Mr. Mukhtar, so frail in his old age that it's difficult for him to move from the cushioned bench in his home. But his legendary father still inspires many youth in Benghazi; the spray-painted slogan on the burned shell of a government building reads: "Omar Mukhtar said WE DIE OR WIN."
Col. Gadhafi apparently feared the dead hero's influence, removing a shrine in his honour from a central roundabout in the city. Nothing remains of the marble arches, inlaid with precious stones, except a weedy vacant lot - and a flagpole, now fluttering with colours of the new revolution.