BAMAKO Suicide attacks on a French-run mine and a military base in northern Niger have shown how an Islamist threat is spreading across the weak nations of the Sahara, meaning France may be tied down there for years to come.
Regional rivalries are aggravating the problem for Paris and its Western allies, with a lack of cooperation between Saharan countries helping militants to melt away when they come under pressure and regroup in quieter parts of the vast desert.
Security officials say lawless southern Libya has become the latest haven for al Qaeda-linked fighters after French-led forces drove them from strongholds in northern Mali this year, killing hundreds.
"The south of Libya is what the north of Mali was like before," said a senior adviser to Mali's interim President Diouncounda Traore, asking not to be named.
Niger has said last week's suicide raids, which killed 25 people at the army base and desert uranium mine run by France's Areva, were launched from Libya. Amid growing tensions between the two countries, Libya has denied this.
Chad, which played a leading role in the Mali campaign, said a man was shot dead in an attack on its consulate in the Libyan desert town of Sabha at the weekend.
Smugglers have long used Libya's poorly patrolled south - a crossroads of routes to Chad, Niger and Algeria - for trafficking drugs, contraband cigarettes and people to Europe.
But the overthrow of Muammar Gaddafi in 2011 flooded the Sahara with pillaged weapons and ammunition. Tuareg separatists used them to seize power in northern Mali, only to be ousted by even better-armed Islamists who set up training camps and imposed harsh Islamic law until the French forces arrived.
The Islamists have also exploited Libya's weakness. Veteran al Qaeda commander Moktar Belmokhtar bought weapons there after Gaddafi's fall and his fighters passed through southern Libya to carry out a mass hostage-taking at an Algerian gas plant in January, in which 37 foreigners died.
A spokesman for the MUJWA, an al Qaeda-linked group which controlled parts of Mali last year, told Mauritania's al Akhbar news site that the Niger attack was not prepared in southern Libya. But Belmokhtar's group said it also took part.
With no effective national army, Libya relies on local brigades to police its southern border region where at least 100 people died in ethnic violence last year. Tripoli's failure to restore security there may be encouraging permanent Islamist camps and weapons stores, security officials say.
France, which relies on neighbouring Niger for one fifth of the uranium powering its nuclear reactors, has urged regional powers to cooperate to tackle the threat from Libya.
"We're extremely concerned that what's happening in southern Libya could replicate what happened in Mali," a French diplomatic source said, adding that the defence minister had raised the issue on a recent visit to Washington and London. "Dealing with that problem needs to be fast-tracked."
Paris is keen to cut its troop numbers in the region. But, amid persistent bickering and mistrust among regional powers, President Francois Hollande admitted last week that French forces may have be used elsewhere in the Sahel.
Alarmed European governments also approved a 110-man mission this week to improve border security by training Libyan police and security forces. [ID:nL6N0E34Q0] But Paris feels this is being deployed too slowly, given the urgency of the situation.
"As much as the West may wish to leave the problem to Africans, it cannot," said Vicki Huddleston, a former U.S. ambassador to Mali. "Islamists will continue to fight until defeated by the region working together and supported by Western governments."
LACK OF COOPERATION
Borders often have little meaning in a desert where militants can blend in with nomads, and hunting Islamists requires states riven by mutual suspicion to work together.
Algeria, the Sahara's main military power, has long bristled at the idea of outside intervention in the region, particularly one led by its former colonial ruler, France.
It allowed French war planes operating in Mali to fly over its territory. But the Malian official said Algeria had to be more active, whether by arresting militants or preventing the flow of fuel that allows them to cover vast desert distances - the northern Mali town of Gao lies about 1,500 km (930 miles) from the border of southern Libya.
"Algeria's cooperation is essential but they are not on the frontline," he said.
Mauritania also needed to do more because of its strategic location on the western edge of the Sahara, the high number of its citizens who are senior militants, and its experience in tackling Islamists at home, he said.
U.S. officials said efforts to tackle the spreading influence of al Qaeda's Sahara branch had been beset by long-standing rivalries, notably between Morocco and Algeria, and a lack of trust and communication between regional capitals.
Plans to set up a Saharan anti-terrorist command center in southern Algeria never materialised. A low point, officials in Mali's interim government say, was reached in 2011 when senior figures in the previous administration leaked the positions of Mauritanian troops attacking al Qaeda bases in Mali.
Relations between Mali and Mauritania had already soured in 2010 when Bamako released a Mauritanian al Qaeda commander in return for a kidnapped hostage, prompting Nouakchott to recall its ambassador.
The changing face of Islamist militancy creates particular problems for governments. For years Al Qaeda's North African wing AQIM relied largely on Algerians but they were joined last year by gunmen from across northern and parts of West Africa.
The MUJWA group includes more black Africans better able to drift unnoticed between West African nations since France's onslaught. "They have deployed to other theatres," said Soumeylou BouBeye Maiga, a former Malian foreign minister and security chief. "They will take on France elsewhere as there is a concentration of forces here."
Niger's long border with Mali, tough line on tackling the militants and role as a supplier of uranium to France have long made it a target. U.S. troops are training the army and Niamey has stepped up security in the north, where French Special Forces went this year to protect mines. Four French mine workers seized in Arlit in 2010 are still being held.
U.N. conflict expert Ismael Diallo said France, which had originally ruled out using ground troops in Mali, was gradually being dragged deeper into policing the region.
"France has no choice," said Diallo, a former senior official in Burkina Faso. "Regional cooperation will not improve soon enough and to a credible level to deter the armed groups."
"WE ARE WATCHING"
In Mali, drone surveillance and counter-terrorism teams on the ground have done much to stifle the militants. Suicide attacks around the northern towns of Gao and Menaka this month claimed no victims apart from the bombers themselves.
According to French officials, about 600 Islamists have been killed in "Operation Serval", named after a desert wildcat.
About 200 tonnes of ammunition and dozens of vehicles were seized in operations that scoured desert and mountain bases, disrupting arms and fuel dumps that the Islamists prepared during their nine-month occupation of northern Mali.
"They don't seem to have the ability to coordinate attacks in Mali anymore," said a French officer in Mali. "We assume that they will try to regroup but it will take time for them and it is risky as they know we are watching."
French operations have been backed by a British spy plane and U.S. drones operating from Niger alongside an established monitoring base in Burkina Faso.
But Islamists who once traveled in large convoys have adapted and are keeping a low profile. "At any given time, they could be anywhere," said a U.S. official. "People go where the fight is."
(Additional reporting by John Irish in Paris, Laurent Prieur in Nouakchott, Richard Lough in Addis Abba; Editing by Daniel Flynn and David Stamp)