I suggested to readers of this column in October last year to watch this space.

In the coming months I fully expect to be writing about an international military intervention in the West African country of Mali.

Well, at the risk of sounding smug, here we are in the throes of just such a scenario. As I write, French troops are already spearheading that intervention and engaging jihadist forces in the north of Mali with support from African troops as well as logistical and intelligence back-up from Britain and the United States.

That this deployment comes with considerable risks goes without saying. Already a terrorist backlash and the spread of the conflict across the vast porous borders of the Sahel and Sahara region has begun to manifest itself in the shape of a hostage crisis in neighbouring Algeria.

Over the past few days there Islamic militants overran a BP gas facility, kidnapping and then yesterday killing some foreign and local workers before Algerian forces launched an assault that cost more lives. More attacks across the region and further afield – especially in France itself – are almost certain.

The French Government must, of course, be aware of the risks it is taking. That being the case, why, then, is it so willing to throw caution to the wind and what exactly does it hope to achieve through its military campaign in Mali?

And, if the French have good reasons for their Mali mission, so, too, no doubt do the jihadists who oppose them, and what do they stand to gain in the long term across the region?

To take France first, perhaps it's worth pointing out from the start Paris has in fact very few direct interests in Mali itself. That said, Mali does lie at the heart of France's former colonial empire in a wider West African region where Paris continues to have substantial economic interests.

Think oil and gas in Algeria, uranium in Niger that fuels one-third of French nuclear power stations, gold mines in Mauritania and cocoa in the Ivory Coast and you will get some idea of what motivates the Government of French President Francois Hollande.

At one time, of course, it would almost exclusively have been the US that dominated the mission to degrade and disrupt jihadist forces globally. And, while France's willingness to take on its Mali role is driven primarily by its own security and economic interests, it is also in part due to a change of doctrine and strategy emanating from Washington.

For some time now the Obama administration has taken a step back from certain events in far-off lands where the US has few interests but other allies, like France, do. Libya and now Mali are points in case.

Seen from the jihadists' perspective, meanwhile, Mali has given al Qaeda in the Islamic Maghreb (AQIM) and its affiliates an area in which they can marshal resources, train and plan in order to further their political ends.

Mali is just the latest case of an opportunistic exploitation of failed states and security vacuums the likes of which we have seen previously in their other areas of operation such as Sudan, Afghanistan, Somalia, Yemen and Libya.

Mention al Qaeda and most people think of Afghanistan or Pakistan, but the simple and disquieting fact is that northern Mali has for some time been the largest al Qaeda-controlled space in the world, an area a little larger than France itself.

Jihadists operating there have been linked to Boko Haram, the violent Islamist group based in northern Nigeria, and to Ansar al Sharia, a group in Libya that has been connected to the attack on the US consulate at Benghazi that killed Ambassador Chris Stevens and three other Americans.

Only last month General Carter F Ham, commander of the US Africa Command, flagged up that al Qaeda was using northern Mali as a training hub and base for recruiting across the whole of Africa, the Middle East, and even into Europe.

Seen from this viewpoint, security and economic concerns are clearly inextricably connected in driving France's Mali mission.

President Hollande said as much earlier this week when – echoing General Ham's fears – he warned the jihadists in the Sahel and Sahara pose a threat that "goes well beyond Mali".

How all this will play out for his French troops tasked with containing the threat on the ground is another matter and will probably involve three phases.

Already under way is an attempt to stabilise and drive back jihadist incursions around the towns of Diabaly, Konna and Douentza.

This will most likely be followed by building up forces in the area by bringing in units from the Economic Community of West African States (ECOWAS) and rebuilding the beleaguered Malian army. The final military phase will involve a push deeper into northern Mali, seizing key territory and urban centres.

No doubt France will be keen to emulate the success on the other side of the continent of that other foreign-funded regional force, the African Union Mission in Somalia (AMISOM), who have battled back al Shabaab, an al Qaeda-linked group, inside the country. That said, it took the best part of three years for AMISOM to learn how to fight effective urban warfare in the Somalia capital Mogadishu.

And therein must lie France's biggest fear, that of getting mired in a long and bloody campaign against a formidable enemy totally at home among northern Mali's endless sand dunes and rocky mountains.

"France will have to do a lot more than hold the line," was how Gregory Mann, a Mali expert and historian at Columbia University summed it up in a Foreign Policy magazine article a few days ago, adding that France had "a long and integral role to play" in Mali.

Over the years, in responding to events in its former colonial sphere of influence in places like Chad, Ivory Coast and the Central African Republic, France has regularly carried out military operations.

Those, however, were largely policing missions. Mali is altogether something different and, as events in the Algerian hostage crisis showed yesterday, the war against al Qaeda and its affiliates recognises no borders.

Just as an exit strategy for the West appears within grasp in Afghanistan, it seems France has been lured into a new battleground in the war on terror.

How and when it will be able to extricate itself will be well worth watching.