(CNN) -- Within the past few days, French combat forces have deployed to the West African state of Mali to halt the advance of militant Islamist fighters toward the capital and to help the Malian army begin to reclaim towns previously occupied by the militants. After intense airstrikes against rebel strongholds, French ground forces are moving north to try to dislodge the fighters.
Mali is one of the poorest countries in Africa, a vast and sparsely populated land that is largely desert. But events there are being watched with growing anxiety throughout West Africa, in European capitals and in Washington. Why?
1) Location, location, location
Mali is hardly a regional powerhouse and is "marginal" to the world economy. It does not sit on lakes of oil; it is landlocked and desperately poor. But it is very big -- nearly twice the size of France -- with seven neighbors whose long, poorly guarded borders provide militants with supply (and escape) routes.
Many of these countries - from Algeria in the north to Ivory Coast in the south -- have themselves seen violence, extremism and instability and are ill-equipped to deal with the fallout from Mali imploding.
To the west, Mauritania has its own problems with Islamist militants associated with al Qaeda. Neighboring Niger to the east has, like Mali, seen frequent rebellions by ethnic Tuareg separatists.
To the north, the Algerian government still has its own al Qaeda problems. In the 1990s an Islamist insurgency and its repression claimed at least 100,000 lives. Militant cells remain active in the eastern mountains and in the desert bordering Mali, where troop convoys have been ambushed on several occasions.
Despite lingering animosity toward France because of colonial rule, Algeria has taken the unprecedented step in the past few days of allowing French military overflights to monitor the extremists' movements. That's because, according to analysts, it sees a growing danger of militant groups coalescing. To try to prevent militants infiltrating, Algeria has closed its border with Mali and deployed some 30,000 troops to border regions. Mauritania has also tried to protect its border.
Mali also sits astride some of the most lucrative smuggling routes from Africa to Europe, routes that militants have turned into a cash machine. At one point, drug traffickers from South America were flying aging jets packed with cocaine into a remote desert airstrip in Mali, for shipment to Europe.
So vast and inhospitable are the deserts of North Africa that groups with local knowledge (and a fleet of 4 x 4 vehicles) can make serious money from trafficking, whether in drugs, people or other contraband.
2) Ungoverned space
In Mali and throughout much of West Africa, the lack of state authority is nirvana to extremist and criminal groups. Across a largely Muslim area stretching from the Mediterranean to northern Nigeria, deprivation and corruption are recruiting sergeants for militant Islamist groups: al Qaeda in the Islamic Maghreb (AQIM), the Movement for Jihad and Unity in West Africa (MUJAO), Ansar Dine and Boko Haram.
The current crisis has been some time in the making. A U.S. diplomatic cable from 2009 quoted a senior Algerian official, Abdelmalek Guenaizia, who complained that "the nexus of arms, drug and contraband smuggling in northern Mali created an enabling environment" for terrorists, who would "use any means available to finance their activities, including corruption and hostage-taking."
Guenaizia warned then that AQIM was increasingly capable. They "use the best explosives, have honed their bomb-making expertise and use sophisticated means to deploy explosives against their targets," he said.
AQIM comprises largely Algerians, Mauritanians and Malians. Experts say its total strength is probably in the hundreds rather than any more. But the fall of Gadhafi opened up a black market arms bazaar across North Africa, and western intelligence agencies believe AQIM may have acquired anti-aircraft missiles along with other heavy weapons, as well as plenty of vehicles, essential in a region of few (and dilapidated) roads.
As jihad became more difficult elsewhere -- from southern Yemen to the tribal territories of Pakistan -- foreign fighters also began appearing in Mali. Reports from the northeastern town of Gao in recent months said Pakistani and Saudi militants had been seen there.
There is the risk that global jihad's center of gravity could shift from South Asia to North Africa.
"We have a responsibility to make sure that al Qaeda does not establish a base for operations in North Africa and Mali," U.S. Defense Secretary Leon Panetta told reporters Monday. "While they might not have any immediate plans for attacks in the United States and in Europe, ultimately that still remains their objective."
The current crisis in Mali began in January last year, when a rebellion by ethnic Tuaregs (helped by weapons brought from Libya as the Gadhafi regime crumbled) erupted. Mid-ranking officers in Mali's army then launched a coup against a civilian government largely seen as weak and corrupt, and in some instances complicit with the militants for its own financial benefit.
Ansar Dine (Defenders of Islam) seized upon the chaos. The group was formed and led by Iyad ag Ghali, a Tuareg who had become radicalized during time in Saudi Arabia. While the main Tuareg rebel group, the National Movement for the Liberation of Azawad (known by its French acronym, MNLA), did much of the early fighting, Ansar Dine took control of cities such as Timbuktu as government forces fled.
By the spring of last year, Northern Mali had become the "largest territory controlled by Islamic extremists in the world", according to U.S. Sen. Christopher Coons, D-Delaware, chairman of the Senate Foreign Relations subcommittee on Africa.
A video released last week by al Sahara Media Foundation, which is affiliated with AQIM, showed that militants had deployed heavy weapons around Timbuktu's airport, including truck-mounted machine guns and rocket-launchers.
And then Ansar Dine made a sudden move south, seizing the town of Konna and threatening the more important city of Mopti and its airport.
Just why is unclear. Some analysts believe they were trying to force the government's hand ahead of talks in neighboring Burkina Faso. But the militants had brought together as many as 300 pickup trucks, according to a French source, and smuggled copious amounts of gasoline in from Algeria. A thrust toward the capital, Bamako, was feasible.
France decided to respond immediately.
"We must stop the rebels' offensive, otherwise the whole of Mali will fall into their hands -- creating a threat for Africa and even for Europe," said the French foreign minister, Laurent Fabius.
3) Exporting jihad
The greatest risk of the Mali campaign is that it will actually nurture the very threat that Fabius worries about: serving as a recruiting sergeant for jihadists, to rally the faithful against a "crusader" enemy in Muslim lands. Two jihadist sites -- the Sinam al-Islam Network and al-Minbar Jihadi Media Forum -- have already urged support for fighters in northern Mali, saying, "Rise O servants of Allah, let us set a fire under the feet of the falling French cross."
There is also the danger that extremists among the 5 million Muslims in France, the vast majority of them of North and West African origin, may seek revenge for French intervention. Less than a year ago, French intelligence services moved against militant cells after a young gunman who had traveled to the Pakistani tribal territories shot dead seven people in Toulouse.
President Francois Hollande has already ordered tighter security in public places.
"France is watching individuals who want to go to Afghanistan, Syria and the Sahel," said Interior Minister Manuel Valls. "We're watching those who could return here."
Mali's neighbors could also be drawn in if they support the French intervention. Algeria has gone to great lengths to insulate itself from Mali's turbulence, but Wednesday a militant group known as Qatiba -- led by a veteran Algerian jihadist, Mokhtar Belmokhtar -- attacked a gas installation in eastern Algeria and claimed afterward to be holding dozens of foreigners. The group said the attack was in retaliation for Algeria permitting French overflights as part of its operations in Mali.
For the Algerians, the assault on a critical part of its vital gas industry was a major embarrassment.
Security analysts said another group of militants appear to have attacked a Malian town from neighboring Mauritania.
Thirty thousand French citizens live in West Africa; eight are already held by Islamist extremists. Senegal has stepped up security in the capital, Dakar, especially in locations frequented by foreigners. And a former U.S. ambassador in Nigeria, John Campbell, writes on the Council on Foreign Relations website that many Nigerians believe the local group Boko Haram has developed links with AQIM.
"If such links do exist on meaningful terms, it would seem likely that Boko Haram will escalate their attacks in northern Nigeria in solidarity with its Islamic brothers," he writes.
4) The soul of Islam
Twelve years ago, Mali was one of six developing nations invited to attend the G8 summit in Italy, and was seen as a beacon of civilian rule and stability in Africa. After chronic instability in the years after independence, it achieved a peaceful transfer of power from one democratically elected president to the next in 2002. (The presidential election set for April 2012 never took place in the aftermath of the coup.) It had a thriving press and lively radio stations. Women had a role in public life. Indeed, in 2011 the prime minister was a woman.
Despite their country's poverty and frequent food shortages, Malians had a reputation for moderation and tolerance, and a rich history as one of the intellectual centers of Islam.
Most Malians are of the Sufi tradition -- a mystical interpretation of Islam that includes a reverence for saints and is despised by puritanical Sunnis.
The city of Timbuktu (sometimes called the city of 333 saints) was a religious and educational center in the 15th and 16th centuries, and its libraries had priceless collections of Islamic documents and books. Its tombs and mosques comprise a UNESCO World Heritage Site, and attracted scholars and tourists from all over the world.
Ansar Dine set about destroying those tombs, insisting they were idolatrous. Throughout the past few months, there have been reports of Malians' shock at seeing public floggings and amputations in areas controlled by militant groups. Radio stations were ordered to stop playing music and instead broadcast verses from the Koran.
UNESCO's secretary general, Irina Bokova, said last July, "The attack on Timbuktu's cultural heritage is an attack against this history and the values it carries -- values of tolerance, exchange and living together, which lie at the heart of Islam. It is an attack against the physical evidence that peace and dialogue is possible."
Mali's glorious musical tradition derived from poets known as griots, highly influential teachers and guides. From this background has blossomed an extraordinary succession of world-class musicians (Ali Farka Toure, Tinariwen, kora player Toumani Diabate and the Super Rail Band to name just a few) who have won fans as diverse as Jimmy Page and Ry Cooder.
So as much as it is a military and political battle, the struggle for Mali's future is also cultural and religious. It pits a tolerant Islamic tradition -- which celebrates music and in which women have a public life -- with an ascetic interpretation that bans music, forbids education of girls and destroys ancient tombs and shrines as "idolatrous."
5) A humanitarian crisis
Hundreds of thousands of Malians are now either refugees in camps outside the country or internally displaced. Most are dangerously prone to malnutrition and disease. There are at least 150,000 refugees now in neighboring countries. More than 50,000 live in one camp alone in Mauritania, where Doctors Without Borders has found chronic rates of malnutrition among children. Malaria and diarrhea are killing infants.
"It is hard to say when the refugees will be able to return home, but many have already suffered as a result of this crisis," said Karl Nawezi, head of the non-governmental organization's operations in Mauritania.
"The influx of refugees is far from over," he said. And many families are tempted to leave the relative safety of the camps because they are herders who need to return to their animals.
Additionally, some 200,000 Malians have fled south to escape the Islamists. Even today, they are still arriving in towns like Segou as the battle lines to the north shift in the sands.
"Many are tired, distressed and in need food and water," said Michelet William, Mali director of the British agency Plan. "We fear our already stretched resources will not last long."
Children are being recruited in the hundreds as militant fighters for the promise of food and a small wage.
Without a quick end to fighting and substantial humanitarian aid, a generation of young Malians will remain at grave risk, imperiling the country's future.
6) A test of international will
Mali is now a test bed for the effectiveness of international action against militant Islam in Africa -- action that brings together very different capabilities and cultures and that has an ill-defined goal.
Much depends on how groups like Ansar Dine and others respond to the offensive. If the militants scatter into the desert and Malian troops can reclaim the main towns, partial victory can be claimed. But if they hunker down and mix with civilians -- much as clans in Mogadishu did in 1992 -- France could find itself in an ugly war of occupation and suicide bombings, with insufficient troops (2,500 spread thin over a huge area) to provide security.
This "would raise the political costs of the French bombing campaign, dragging the intervention into urban warfare that neither France, the U.S. nor Algeria would be willing to lead with boots on the ground, and leaving Mali's fractious military exposed," according to Phillippe de Pontet of Eurasia Group.
The United States has made clear it cannot help train the Malian army until a legitimately elected government is in place, but it will provide satellite intelligence and intercepts. France has no viable drone capacity of its own.
The role of the African force and its capabilities are unknown factors. Diplomats expect some 3,300 troops from seven or eight countries belonging to the regional grouping known as ECOWAS (the Economic Community Of West African States) to arrive in Mali over the next week or so. The largest contingent will be from Nigeria, and the force will have a Nigerian commander.
They will need airlift help -- which has been promised by the United Kingdom, Belgium and Germany, and in which the United States conceivably could participate -- and are likely to be deployed in a holding role while French and Malian forces push north.
But their ability to work together and fight, should Ansar Dine militants somehow evade the Franco-Malian advance, is very much in question. They have not trained together, and they have different structures and languages. In addition, some contingents will be no more than a token force of 100 men.
This is an ad hoc "coalition of the semi-willing." Some French officials have begun grumbling that other European states are doing too little.
Even if Ansar Dine and other jihadist groups can be broken up, Mali's military and its political institutions have been shredded by the chaos of the past year, and its population is debilitated. The "Tuareg question" remains unsolved, with southerners now even more hostile to Tuareg separatism.
Many MNLA fighters are said to have fled west into Mauritania rather than get caught up in the showdown between the French and the rebels.
The French may profess satisfaction at scattering Ansar Dine, thanks to months of painstakingly compiled intelligence on the group's bases. President Hollande has pledged French forces won't leave until Mali has security, legitimate authorities, an electoral process and no more terrorism.
But these are early days in the campaign dubbed by the French military Operation Serval. The serval is an agile desert cat. But it is also an endangered species.