Siege awakens ghosts of Algeria's 'dirty war'
The twin crises unfolding either side of the Sahara Desert in Mali and Algeria are closely interlinked - the Islamist groups in Mali have their roots in Algeria, while the kidnappers who have just struck in Algeria say they are acting in revenge for France's intervention against their allies to the south.
While some analysts have said it would have not been possible to plan and carry out such a complex operation in the few days since the French intervention in Mali, the well-connected Islamist groups who operate across the Sahara Desert are likely to have had sleeping cells, allied commandos in Algeria and beyond and local sympathisers ready to join in if any high-profile operation was decided.
The hostage crisis on a BP oil base at Tigantourine in southern Algeria brings the issue of Islamist groups back to Algeria, where they developed in the early 1990s before the army routed them, forcing their relocation in Mali where ex-President Toumani Toure had the weakness to tolerate them.
The Malian crisis is, to a large extent, the by-product of a conflict which has been mostly forgotten these days, but which cost the country between 70,000 and 150,000 lives during Algeria's so-called "dirty-war" (1991-2002).
Algerians represent an overwhelming majority of the leadership of jihadist groups in northern Mali.
Trained and first exposed to combat in Afghanistan during the war against Soviet invaders (with the blessing of Western supporters), they soon imported back their knowledge of guerrilla tactics and used it to fight the central government after the democratisation process was brutally halted in 1992, just between two election rounds.
With the prospect of the Islamic Salvation Front (FIS) winning the elections on a religious-populist programme, the ruling National Liberation Front party, in power in a single-party system since independence, prevented the Islamists from gaining power legally.
Though some Islamists remained legal, the clamp-down on their parties led to the quick development of armed groups which first managed to control some areas of the Algerian territory, before being gradually defeated at the price of a long and bloody conflict which left the civilian population so traumatised that it abstained from rising up when the rest of the Arab world was swept by revolutions in 2011 and 2012.
Having been defeated militarily, the Islamist groups were forced to leave the resourceful maquis of northern Algeria, where camouflage had been relatively easy but insufficient to ensure their survival against a regular army increasingly on the offensive and committed to their eradication.
They were gradually repelled towards the Saharan regions, until the army gained enough momentum, and knowledge of warfare in desert environments, to force them out of Algeria altogether.
Most of them relocated in northern Mali, where they had the opportunity to create links of kinship by marrying local women, the dowries of whom could be paid easily with the money made out of the abduction of European travellers (for whom hefty ransoms were usually paid) or drug-trafficking.
Well-integrated into the local social fabric, they also created synergies between their own agenda and the long-standing Tuareg problem, which has led to five uprisings so far in Mali and Niger since independence in the 1960s.
Besides, there have been persistent reports that the Algerian secret services might have been happy to lend a helping hand to this relocation, which not only allowed them to eliminate the problem of armed Islamists at home, but also gave Western governments a constant reminder of the risk looming over the region, therefore propping up foreign support to the Algerian government, in spite of its limited democratic credentials.
Sensing the inevitable side-effects of any military intervention in the Sahara, which had the potential to push back home the Islamist problem, the Algerian government has tried for a long time to promote a negotiated solution to the stalemate in northern Mali.
However, one of their main partners in this strategy, the Tuareg-led Islamist group Ansar Dine, which they hoped to talk into leaving the coalition with terrorist groups AQIM (Al-Qaeda in the Islamic Maghreb) and MUJAO (Movement for Unity and Jihad in West Africa) it had entered into, has betrayed them by taking part in the offensive against the Malian government.
By breaking the fragile status quo prevailing since the spring of 2012, it triggered the current French-led military operation in an attempt to avoid a complete collapse in Bamako.
By agreeing to open Algerian airspace to French fighter jets on their way to Mali, and to close its southern border, Algiers has unwillingly relapsed into an old war it knows only too well.
Unable to confront the firepower of the modern weaponry of the French army, Islamist fighters have found a parade in guerrilla tactics and also by exporting the war to neighbouring countries as much as possible.
Among them, Algeria is naturally a key target for historical, logistical and symbolic reasons.
Historically, it is the cradle of armed Islamist struggle in North Africa.
Logistically, it still counts sturdy sleeping cells which can be easily reactivated whenever necessary.
Symbolically, striking a BP base-camp for oil workers sends a powerful message to the Algerian government, by threatening a vital national industry and defying the country's efforts to eradicate terrorism on its own territory.
It is as if the old ghosts of the "dirty war" came back from the sands of Mali to haunt Algiers, bringing home the spectre of armed groups which it had taken the Algerian army a decade of great efforts to expel.