大象传媒

It is just before 15:00 on Saturday in Timbuktu and the intense desert heat has reached its peak.

Five years ago, Islamist occupiers were driven out of the historical town - but violent extremists have never been far away.

A few people are browsing through the silver jewellery and leatherwork at a small Tuareg curio market by the security checkpoint at the airport entrance.

It鈥檚 on the outskirts of town and both French troops and UN peacekeepers have set up what they call a 鈥渟uper-camp鈥� there.

At this sleepy time of day, people are working inside their air-conditioned containers and all that can be heard is the low hum of generators.

Then, blaring sirens.

Everyone - whether inside the base or shopping at the market - knows immediately they have less than 30 seconds to reach a bunker.

The early warning sirens mean a mortar or rocket attack is incoming.

One of the shop owners, Amadou (not his real name) knows what to do - he rushes everyone at the market, including four American soldiers, into a small bunker nearby.

Twenty six people are crammed into the small space protected by sandbags - five of them young children.

Then comes the terrifying whistle and crash of mortars.

About a dozen cut through the hazy, sand-soaked sky, exploding in and around the super-camp next to the terminal.

Amadou can see the American soldiers are keen to get to their car and back inside the camp, but he tells them to wait for an all-clear. That saves their lives.

Troops at the first checkpoint are on high alert because of the mortar attack.

But two Malian military vehicles race up, apparently desperate to get inside. Their vehicles aren鈥檛 armoured and they are out in the open.

Neither stop to be searched as they swing around the sand-filled bollards at the gate and accelerate through the checkpoint.

From his hiding place in the bunker, Amadou hears the car and then the scream of 鈥淎llahu Akbar [God is greatest]鈥�, just before a huge explosion a few metres away.

The first suicide bomber has detonated his explosives-laden vehicle at the first checkpoint, clearing the way for a second bomber to speed through.

The blast rumbles through the camp and the atmosphere inside the bunker changes dramatically.

The children start crying as gunfire erupts around them. But the Islamist fighters don鈥檛 know they are there.

Amadou can see people are about to flee the bunker in fear, but the US troops tell everyone to stay down and stay quiet. That saves their lives.

Further up the road, the second bomber accelerates towards French soldiers guarding their section of the camp and explodes right in front of them.

With the outer defences breached, jihadist foot soldiers in Malian military uniforms rush in - at least three of them wearing suicide vests - and so begins an intense battle.

The airport terminal building is almost destroyed.

For three hours, the attackers are repelled. For three hours, 26 people hide in a bunker - terrified they will be found and killed. The four American soldiers are armed only with pistols.

They radio for help but it is only after 18:00, as the Sun is setting, that the gunfire finally stops and a rescue party reaches them.

As everyone in the bunker is rushed inside the super-camp, Amadou sees the dead body of an attacker lying close to what is left of his store.

But then comes a third car bomb - again at the main gate - perhaps to help the surviving attackers retreat. A fourth unexploded car bomb is found later.

The attack is finally over.

One UN peacekeeper, from Burkino Faso, was killed and seven others were seriously injured. Seven French soldiers and two civilians were also badly hurt.

On the militant side, French forces said 15 had died.

The al-Qaeda-backed group JNIM (Jamaat Nusrat al-Islam wal-Muslimin) claimed responsibility for the most sophisticated attack so far on a military base in Mali.

Timbuktu was once at the heart of the Mali Empire. The king is said to have been the richest man ever to have lived - a 14th Century multi-billionaire.

When Mansa Musa I went on the Hajj pilgrimage to Mecca, he brought tens of thousands of courtiers with him, and lavished so many gifts of gold along the way that the price of the precious metal crashed in Cairo.

Mali was an empire built on gold but it also grew rich on trade - in metals, salt and slaves. Traffickers have been making fortunes for centuries moving commodities across the Sahara.

For 250 years, the Mali Empire grew into a centre of learning for science, literature, religion and art.

Scholars from all over the Arab world travelled to the towns that cling to the River Niger as it arcs through the desert - to Timbuktu, Djenne and Gao, where mud mosques were built, and beautiful Islamic scripts were painstakingly written and illustrated.

Djenne鈥檚 grand mosque is the largest mud-brick building in the world. Until recently Mali鈥檚 rich history attracted hundreds of thousands of tourists every year.

But all that changed in 2012, when the extremists moved in.

Mali鈥檚 road to chaos led straight from Libya.

In 2011, the country collapsed as Arab spring protests led to civil war, Western intervention and the death of Col Muammar Gaddafi.

Armed Tuareg mercenaries who had been fighting for Gaddafi headed back home to Mali with renewed purpose, and with weapons.

For decades, separatists had been demanding independence for northern Mali. In 2012, Tuareg rebels fighting in a convenient partnership with al-Qaeda-backed Islamists drove the army out and declared an independent state of 鈥淎zawad鈥�.

The name of their new state is thought to be an Arabic corruption of the Berber word 鈥渁zawagh鈥�, meaning 鈥渄ry river basin鈥�.

As the rebellion spread across northern Mali, disgruntled, underpaid troops staged a military coup in the capital throwing the country into chaos.

The lack of leadership or military response meant the northern uprising was able to spread out of control.

The religious extremists imposed strict sharia law. In Timbuktu and beyond, they smashed shrines built for Sufi mystics, burned manuscripts and destroyed ancient artefacts.

The priceless texts would have all been lost had it not been for the old guardian families who protected what they could.

Tuaregs and Islamists disagreed over the way their new state of Azawad should be run and began to fight each other.

The government asked for foreign military help and the former colonial power France answered the call.

French troops arrived in January 2013 and were joined by African forces. Within a month, they had driven the violent extremists out into the desert and retaken the River Niger towns.

The Islamists were down, but not out.

Neighbouring countries and the United Nations came in to support a peace deal between the government and rebellious Tuareg armed groups.

That deal still holds and their guns are broadly silent but good governance has failed to return.

And a far more lethal Islamist threat has returned from the desert.

The extremist groups have gradually been strengthening and uniting and as the dangers have increased, UN troops have taken fewer risks - spending longer in their bases, leaving the desert ungoverned and vulnerable.

Many foreign flags fly over the UN super-camp in the northern Malian town of Gao.

Cambodian troops roll out their bomb-defusing robot, Chinese peacekeepers run the hospital and patrol inside the base, while a carved Pharaonic column overlooks the compound of the Egyptian convoy protection unit.

On the parade ground, the wail of badly tuned bagpipes wafts above the lines of Bangladeshi soldiers, practising for their departure parade just weeks away.

Different countries accept different levels of risk. Many are simply going through the motions - counting down the days, trying to stay alive, and having little real impact in a place where it鈥檚 nearly impossible to keep the peace.

Heavily armed Senegalese police in big UN armoured vehicles trundle out of the base and stop at the local police station to escort the commander on his beat through a Gao town bathed in darkness.

Their presence is a target. It鈥檚 a lot of risk and effort for just a few minutes out meeting people huddled around TV screens watching live European football.

Gao is increasingly becoming a central hub for people trafficking. The Islamist threat is growing and the dangers are increasing.

鈥淎ll the citizens are scared about the terrorists,鈥� says one man sitting by his motorbike.

鈥淪ometimes they steal the vehicles and kill people so this is not good for us - that is why we are scared.鈥�

On a dusty scrap of desert in northern Niger, the runway at Airbase 201 is gradually taking shape.

A squadron of rollers driven by American troops is readying the long strip of land for a thick layer of asphalt.

First planned as a drone base, it鈥檚 going to be far more than that - costing $110m, it鈥檚 long enough to land some of America鈥檚 biggest military cargo planes and will be home to 800 service personnel.

The US says it鈥檚 just temporary and it belongs to Niger. But Airbase 201 is unmistakably American and undoubtedly being built to last.

It鈥檚 concrete evidence of how America鈥檚 military footprint is spreading across the Sahara.

Just beyond the perimeter fence is Agadez 鈥� a former tourist town, which over the past five years has been transformed into the most important hub of the trans-Saharan migrant trade.

Economic migrants have always moved through here, ready to head north across the desert.

But in the chaos of Libya鈥檚 collapse in 2011, this trail became a highway.

Criminal gangs moved in and the desert tour guides became human traffickers, carrying lorry-loads of migrants north to the shores of the Mediterranean Sea.

This thriving industry provides both cash and cover for the radical, violent, extremist groups assembling across the Sahara.

But with corrupt officials taking their cut, there鈥檚 little incentive to shut down the trafficking and isolate the Islamists.

鈥淵es, of course I鈥檓 frustrated,鈥� says the head of Nigerien special operations, Col Maj Moussa Salaou Barmou.

鈥淭he violent extremist organisations are involved in these illegal migrations. They are making a lot of money out of it.鈥�

The head of Special Operations Command Africa, Maj Gen Mark Hicks, says the Sahel is vitally important because of the growing strength of the al-Qaeda- and IS-affiliated groups.

鈥淚f we don鈥檛 take this opportunity to deal with it now, where it鈥檚 at a level that鈥檚 affordable and sustainable both in blood and treasure, then it may cost much, much more to deal with it at a later time,鈥� he says.

The US recently led the annual Operation Flintlock training exercise, bringing together 12 African and eight Western nations.

For African countries, it was a chance to learn how Western armies worked, and for the visitors it was an opportunity to find 鈥減artners鈥� who could help fight foreign terror for them.

The US Special Operations soldiers are training regional forces - sharing their skills with poorly trained and equipped African troops.

鈥淭o work by, with and through our African partners and our Western partners as an international coalition of the willing鈥� - that鈥檚 the military jargon Maj Gen Hicks repeats. It has echoes of Iraq and Afghanistan.

As rich nations baulk at losing men in a distant desert, these African troops are the boots that will ultimately be on the ground fighting a war on terror for them.

Blue helmets no longer give the protection - or the sense of neutrality - they used to.

Given the proximity of UN bases to the counter-terrorism units, their heavily armed appearance and a mandate to open fire, the lines are blurring.

That鈥檚 why Mali is now the most dangerous UN peacekeeping mission in the world.

The 鈥渨ho鈥檚 who鈥� map of most wanted men, and their groups across the Sahel, is a bewildering family tree of alliances and allegiances, old photographs, and long French or English acronyms.

Extremist groups have grown and divided, splintered and reformed, as those backed by al-Qaeda and the Islamic State group battle for power and influence.

Boko Haram, and its offshoot, the Islamic State in West Africa Province, have displaced and terrorised hundreds of thousands of people in north-eastern Nigeria and the bordering countries of Niger, Chad and Cameroon.

Splits in the leadership and a concerted effort by the Nigerian army has eaten into their influence, but the kidnap of schoolchildren and the use of young suicide bombers continues.

But it鈥檚 further west - mainly in Mali and the border regions of Burkina Faso and Niger - where attacks are increasing in frequency and sophistication.

Currently, the most powerful group is known as JNIM, which was formed in March 2017 when four al-Qaeda-backed factions merged, overcoming years of splits and divisions over strategy and ideology:

- al-Qaeda in the Islamic Maghreb (AQIM)

- al-Mourabitoun

- Ansar Dine

- Macina Liberation Front

The coalition鈥檚 leaders include former Tuareg rebel leader Iyad Ag Ghaly and veteran jihadist Mokhtar Belmokhtar - whose death has been reported on a number of occasions

JNIM carried out the recent attack on the military base at Timbuktu airport and regularly targets UN and other military convoys with bombs or ambushes.

Its militants have also bombed popular hotels and restaurants in regional capitals in West Africa and attacked civilians in remote villages.

United, the four groups are a much more effective force, each with their own area of influence, sharing intelligence and bomb-making technology.

But there are even more groups to add to this complex picture.

You can see the problems in the historical Malian town of Mopti. There, the River Niger is particularly low for this time of year.

The boats that were once packed with tourists are tied up on a beach strewn with plastic rubbish and waste.

Drought is just another blow to the central part of this country that once welcomed tens of thousands of visitors every year wanting to explore its rich past.

The UN says five million people across the Sahel are in need of food aid. More than 1.5 million children are at risk of malnutrition.

Climate change is bringing more extreme weather. There are now few fish and no tourists - the violent extremist groups are close by. Attacks are increasing and young people are being radicalised.

鈥淭he government has abandoned this corner of the country. In the last five years, the state has not been present here,鈥� says Djougal Goro, leader of a youth group in Mopti.

鈥淲hoever knows Mopti, knows that Mopti only lives off tourism. The unemployment rate is very, very high here.

鈥淚f you鈥檝e nothing else to do but hang around, you will eventually be swayed by negative influences and you will be forced to be radicalised. You will be forced to go to their side. That鈥檚 what causes the insecurity here,鈥� he says.

Islamists offer young men hard cash to fight. With no courts to settle land disputes and complex historical, ethnic-based disagreements, their harsh form of justice is becoming the law.

From the gates of the beautiful old Sufi mosque, it鈥檚 a short drive to the other side of the village.

Kontza is split along ethnic lines between the Peul and the Dogon. Relations are so bad they have now become completely separate villages.

They are both Muslim but there are big ethnic issues here, which sometimes go back centuries and often involve land disputes between farmers who plant crops and nomadic pastoralists driving their cattle to pasture.

Climate change is driving the Sahara south and reducing the fertile land, while population growth is increasing the competition for dwindling resources.

The Swedish UN force commander for Sector West, Brig Gen Stefan Andersson, is also on the trip - assessing how the civilians work and what he can do to help.

鈥淲ith the lack of Malian defence and security forces - you have no law and order,鈥� he says. A lack of governance is allowing extremist groups to fill the vacuum.

鈥淭hey can provide something and they will punish people if they steal motorcycles or cattle. So in many cases the villagers are welcoming them,鈥� Brig Gen Andersson says.

He says the jihadists talk to both sides.

鈥淭hey are standing in the middle and also provide some kind of security,鈥� he adds.

And Africa鈥檚 population is growing fast - in Mali and Niger it doubles every 20 years - creating a huge youth bulge.

The lack of education, work and opportunities makes this a prime recruiting ground, creating a new generation of Islamist foot soldiers.

European countries afraid of increasing numbers of migrants, and the Islamists they worry could be hiding among them, are investing heavily in the Sahel to counter the threat.

France has committed thousands of soldiers to Mali and it pushed for the regional G5 force to be formed. That鈥檚 still a work in progress.

Three British Chinook helicopters will soon be supporting the French counter-terrorism operation.

Despite a fluid and increasingly dangerous mission, Mali would undoubtedly be worse off if the UN pulled out more than 14,000 people.

And America鈥檚 presence in Africa is growing, although its drone strikes and special forces missions are governed by secrecy.

鈥淩ight now these threats in Africa are clear, immediate threats to our African partners. But they鈥檙e also threats to Western presence in Africa and they aspire to be threats to the West directly,鈥� says Maj Gen Hicks.

He worries Islamic State fighters fleeing Syria and Iraq will come to the Sahel and 鈥渢hat could be devastating to the security situation across North Africa鈥�.

It鈥檚 an obvious place to come, where weak governance, corruption, ethnic division, drought, poverty, unemployment, population growth and climate change all combine to give Islamists a unique opportunity.

It鈥檚 the new, desert front line in the global war on terror.