NALUT, Libya Aug 22 (Reuters) - Now that Muammar Gaddafi's four-decade rule appears to be over, the disparate groups of rebels who drove him from power could face a graver danger: each other.
Without the cause of fighting Gaddafi to unite them, the fighters from all walks of life must come up with an effective leadership to run a country suffering from factionalism, tribal rivalries and ethnic divisions.
Signs of trouble emerged long before the rebels made their dramatic sweep from the Western Mountain region to Tripoli, cheered by Libyans who will soon want a smooth-running government, jobs, better schools and the oil wealth that rarely trickled down to them during Gaddafi's reign.
Rebels who complained about Gaddafi's alleged human rights abuses as they prepared for battle at the frontlines also spent a great deal of time criticizing their comrades, mainly because they were from a different village, or ethnic group or seemed to have more resources.
Libyan rebel Husam Najjair, an Irish citizen, seemed disillusioned with the rebel movement he joined, leaving everything behind in Dublin.
"There could be some very big problems. Everyone is going to want to run the show. That's when it will get messy," he told Reuters. "Everyone must be disarmed."
Is there one unifying figure who can lead Libya and prevent the rebels from turning on each other? Right now the resounding answer seems to be no.
"There isn't one rebel leader who is respected by everyone. That's the problem," said Kamran Bokhari, Middle East Director at STRATFOR global intelligence firm.
Gaddafi ran the North African oil producing-country like a personal cult, without state institutions that would make any transition easier for the rebels, who have plenty of spirit but lack a proper chain of command.
The most prominent rebel leader is Mustafa Abdel Jalil, chairman of the National Transitional Council (NTC), a diverse group of Gaddafi opponents based in the eastern city of Benghazi.
It consists of former government ministers and longstanding opposition members who represent wide-ranging views including Arab nationalism, Islamists, secularists, socialists and businessmen.
A former justice minister, soft-spoken Abdel Jalil was described as a "fair-minded technocrat" in a U.S. diplomatic cable released by WikiLeaks.
A mild-mannered consensus builder in his late 50s, he was praised by Human Rights Watch for his work on Libya's criminal code reform. Abdel Jalil resigned as justice minister in February when violence was used against protesters.
But like other former members of Gaddafi's inner circle, he will always be viewed with suspicion by some rebels who want completely new faces with no past links to the regime running the country.
The prime minister of the rebels' shadow government, Mahmoud Jibril, a former top development official under Gaddafi, has extensive foreign contacts and has been the rebels' roving envoy.
But his travels have frustrated some colleagues and foreign backers so his experience and contact building will have been wasted if he is not part of any new administration.
Another high-profile rebel who may play a future leadership role is Ali Tarhouni. The U.S.-based academic and opposition figure in exile returned to Libya to take charge of economic, financial and oil matters for the rebels.
Tensions between life-long opponents of Gaddafi and his supporters who recently defected to the rebel side may undermine efforts to choose an effective leadership.
If hardliners prevail, Libya could make the same mistake that analysts say was made in Iraq after the 2003 U.S. invasion that toppled Saddam Hussein.
His Baath Party supporters and army officers were purged en masse, creating a power vacuum that led to instability for years as everyone from his secular backers to al Qaeda waged a violent campaign against Iraq's new U.S.-backed rulers.
"You cannot make a rule that anyone who worked for Gaddafi cannot work with us. It's not practical at all," said Ashour Shamis, a United Kingdom-based Libyan opposition activist.
Such an approach would sabotage any bid to bring back capable people to undertake perhaps the most critical task of all -- revitalizing the oil industry.
Those who want to put aside animosities for the sake of rebuilding the country's energy sector may want to turn to its former top official Shokri Ghanem for help.
Western-educated Ghanem, who defected, has decades of experience in the oil sector and is a former prime minister credited with liberalizing the Libyan economy and accelerating the opening of the country to global petroleum investment.
Bringing people like Ghanem back will depend to a great extent on whether rebels will be willing to put aside their differences and take a practical view of Libya's future.
Judging by realities on the ground, it won't be easy.
Take the Western Mountains region, where rebels recently made the most dramatic gains as they moved in on Tripoli.
The fighters showed far more discipline as they swept through towns and villages in the plains and eventually reached Tripoli.
Beneath the surface, the rebels were torn apart by divisions and factionalism and fears that Gaddafi's agents had infiltrated them. Berber and Arab villages look at each other with disdain.
Rebels refer to themselves as the fighters from village x or village y, not the rebels of Libya. When journalists want to reach frontlines, they are told to get written permission from whichever rebel is in charge of a specific area.
Najjair constantly went on about how his Tripoli Brigade was the best-suited to seize the capital because its members were all from Tripoli. Those same rivalries are likely to linger when it comes time to choosing leaders, from ministers to provincial governors to mayors, and drawing up budgets.
After all, many of the rebels are educated - from doctors to teachers to accountants to engineers - so they are likely to insist on a say on how the country is run.
A hint of what could be in store is the still unexplained July 28 killing of the rebels' military commander, Abdel Fattah Younes, a former top Gaddafi security official, after he was taken into custody by his own side for questioning.
The killing has raised fears that the NTC is too weak and fractured to halt a slide into bloodshed as rival factions, including Islamists, bid for power.
An increasing number of fighters in the Western Mountains, for instance, are growing long, thick beards, the trademark of Islamists who are likely to reject close ties with the West in a new Libya, while others cry out for foreign investment.
They may also argue that the rebels from the Western Mountains and the city of Misrata should be given the most powerful positions in any new government since they did most of the fighting while the ones in Benghazi dealt with administration.
The bitterness was palpable on the frontlines along the desert plains in the West, even though different rebel groups got along enough to stage the advance together.
The rebels from Benghazi were portrayed as outsiders who were often late in delivering weapons and other supplies to their counterparts.
Rebels in the leadership structure will have to figure out ways to defuse tensions among their ranks while trying to turn Libya into a country with a competitive economy.
"Running the country will be much tougher for the rebels. Finding people who everyone accepts will be the challenge," said Bokhari. (Additional reporting by William Maclean in London and Christian Lowe in Algiers; Editing by Ralph Boulton)