"Before the war, trucks entered Libya one or two at a time," says one migrant, a Nigerien named Salem, who works on a farm outside the city of Sabha. "Now it's 10 or 20."
The easy comings and goings through southern Libya are a key component of the security difficulties that have leaders worried for the future. The concern is that a porous border and weak state make the south a natural draw for traffickers and militant groups, a potential whirlpool of instability in an already unstable region.
The Libyan desert, for all its harshness, has been peopled since antiquity. Two millenniums ago, it was home to the Garamantes, who irrigated an area west of Sabha with underground aquifers. Trade routes date to even earlier, as evidenced by prehistoric rock carvings of chariots.
Courtesy of decades of European colonialism, today's national borders cut through ancient tribal, ethnic, and linguistic lines. After former Libyan dictator Muammar Qaddafi fell, state control of Libya's south collapsed, and weapons looted from his arsenals flooded the Sahara. Last December, leaders declared the south a military zone and vowed to seal the southern border.
But that's easier said than done. Just ask Salem, an ethnic Tuareg from Niger who works periodically in Libya. He arrived most recently in Sabha this past February.
Ethnic Tebu, who span several national borders, bring migrants by truck into Libya from Niger, avoiding the main route and using satellite phones to coordinate.
"If there are patrols, we may stop and wait a day or two," says Salem. "If there are no patrols, it just takes a day."
Around 6,000 Libyan soldiers police a desert roughly the size of Texas and Oklahoma, said Ramadan Al Barasi, the south's former military governor, speaking in June, shortly before his posting ended. He said he needed 10,000 to 15,000 men, and that as of June he had received only a trickle of state funding.
For now, southern Libya is open not only to traffickers, but also to militants – including those linked to Al Qaeda – who roam the Sahara and adjacent Sahel region, he says.
Southern Libya's military command is headquartered in Sabha, a low-lying town in the southwest, with irrigated farmland nearby and concentric streets that seem to trace invisible battlements.
Most days life goes ahead normally, but a sense that anything might happen pervades. Tribal squabbles break out periodically, and on June 26, Sabha was struck by car bombs for the first time. Robbers recently pulled off several large bank heists, says Ahmed Zawam, who oversees southern branches of the National Commercial Bank (NCB).
"It hasn't happened to us, but it could happen at any time," he says. With roads deemed unsafe, the NCB now flies money directly from Tripoli to southern branches.
Meanwhile, foreign companies that left in 2011 have mostly stayed away, says Ayoub Zaroug, a teacher who also serves as head of Sabha's local council.
Mr. Zaroug was speaking to the Monitor in his office when eight militiamen marched in, demanding two cars they said the council had promised them. Several carried AK-47s.
Zaroug assured the men that he would look into the matter. As elsewhere, some militiamen in Sabha have been at least nominally brought under state control.
"No one can deny that the revolutionaries protect the city now," he said soothingly. "Even you can call us anytime, and we'll come secure this place!" cried one militiaman with both enthusiasm and desperation.
The men left, and Zaroug allowed the strain to show on his face. Such encounters have twice prompted him to resign. "They need money, and they're not getting support from the state," he says of the militiamen.
"When you have weapons and an absence of security, you can expect trouble."