Thomas Fessy, the intrepid BBC World Service (French) reporter, once again gets to places few do, even if with the French Foreign Legion. A short film clip on patrolling near the Libya-Niger border in the "grey zone" and accompanying longer text:http://www.bbc.co.uk/news/world-africa-31939287

All part of France's 3k strong regional Operation Barkhane, which started in August last year (previous posts in the Mali thread).

He concludes:
The former colonial power, France, today stands as the Saharan policeman and has made it its mission to break the shifting allegiances between extremist groups. But with Boko Haram to the south and an expanding Islamic State to the north, the regional outlook is not too promising.

The last French outpost has some history:
This advanced base is taking shape right next to an old fort that the French army built out of dry mud in 1931 to defend themselves against the Italians, first, and then the British.