Behind the high walls of a family compound in Libya's eastern rebel capital, a giant photo of the late rebel commander Gen. Abdel Fatah Younis smiles down on the dozens of men from his tribe who visit in a large tent after breaking the Ramadan fast on a summer night.

Ali Senussi, a leader of the Obeidi tribe that Younis belonged to, sips tea in a plastic chair, looking grandfatherly in his traditional robe and vest. But as he speaks about the murky circumstances of the assassination of one of the tribe’s own, he doesn’t mince his words. The tribe will give the rebel leadership a chance to investigate Younis’ killing and bring those responsible to justice. But if they don’t?

“The Obeidis are promising this will not go unpunished,” he says. “We hope to be in a country of law and good judgment that ensures our rights without us having to take them ourselves. But if we needed to take our justice by ourselves, we will do it.”

“Tribal law is stronger than the government law,” adds a nearby tribal elder.

The Obeidi tribe’s threat to take justice into its own hands illustrates the challenge that the new Libyan government will face not only in avoiding fighting or division between tribes, but also in ensuring the law reigns supreme over tribal traditions.

During his 42 years as leader of Libya, Muammar Qaddafi whittled away at state institutions, leaving little but himself at the center of the nation. In the vacuum, Libya’s strong tribal identity thrived, as did the divisions between tribes that Qaddafi cultivated. Now, in a new Libya that is likely to soon be free of Qaddafi, a key test will be whether the new government will have enough legitimacy to unite disparate tribes into a cohesive nation.

“Today what remains to be seen is whether Libya's new leaders can break free of the tribalism that has historically plagued the country and move to a more representative and geographically dispersed government,” says Barak Barfi, a research fellow at the New America Foundation who has been in Libya researching the conflict for the past five months. “If they cannot do this, and continue to perpetuate the traditional political order, the new Libya will fail.”

Tribal ties can help with disputes, finding a job

Tribalism runs deep in Libyan history, and tribal leaders are quick to extol the roles of their tribes in fighting Italian colonialism. But tribalism still plays a role in society. For some Libyans, it is not uncommon to go to a tribal leader for help with a problem. Leaders can mediate disputes between members, secure release from jail, and intercede to settle intratribe disputes. For some, a tribal connection can create an instant bond with a stranger or be a means of career progression.

Qaddafi used the system to his advantage, rewarding tribes that were loyal to him and punishing those that were not, creating hostilities between them. As his regime falls, worries of tribal warfare and revenge abound. In western Libya in July, Human Rights Watch reported that rebels had burned and looted homes and shops belonging to Qaddafi supporters. But tribal leaders in the east say that while such violent revenge may happen to the former leader’s most devoted supporters, they do not expect widespread retribution.

“It's not going to happen because all the people are supporting one thing: the revolution,” says Khalil Mohamed El Deeb, a leader in the Agouri tribe, a large tribe in eastern Libya that includes the majority of Benghazi citizens. For example, he says, one of the transitional council’s leaders, Mahmoud Jabril, is from the Warfalla tribe. “They had a really bad role under Qaddafi,” he says. “But we don’t look at him as a Warfalla, we see him as an individual.”

Some also say that the revolution has increased historically weak Libyan nationalism, which could lessen tribalism. “For 42 years, Qaddafi put hatred between the tribes. But this is the first time they feel like they are working together against something, and they like working together,” says Mr. Deeb.

The rebel government has urged citizens to avoid revenge, and it has plans for a national reconciliation program to keep tribal differences from festering.

Can government supersede tribal law?

But perhaps the biggest test is whether the government will be capable enough to supersede the tribal law that some revert to when the government is lacking. Several tribal leaders in eastern Libya asserted that in a democratic nation, tribes would play only social roles, not political ones. Government ministers would be chosen for qualifications, not for tribal membership, they say, and tribes will continue to play roles in taking care of members who can’t afford medical care, sending bright students abroad for further education, and resolving disputes. But the Younis case calls that into question.

Younis was Qaddafi’s Interior minister before he defected to the opposition at the beginning of the uprising and became their military commander. He was killed in rebel custody after he was hastily summoned to Benghazi from the battlefield for questioning. While some have fingered Qaddafi forces for the killing, the Obeidi tribe blames Islamists who are part of the rebel forces, and claims complicity of members of the executive board of the NTC.

The NTC dissolved the executive council in early August in response to pressure from the tribe. But new members were never appointed, and the NTC said this week that the old members would continue to work for two more weeks.

Senussi said the tribe would wait until Qaddafi had been vanquished to take any action in seeking its own justice.

“If the criminals haven't been convicted, and we've gotten rid of Qaddafi and his clients, and Libya is free, we can get the people who did this ourselves, but by a way that is 100 percent legal – obeying the logical law, not the NTC law,” he said. “There are two kinds of law: government law and the tribal or traditional law. We prefer the government law, but if we need to refer to our own law, we will do it.”