By John Rapley

When President François Hollande sent French troops into Mali to shore up that country's beleaguered government, many analysts warned it was just a matter of time before the conflict widened. But as soldiers patrolled the Eiffel Tower to guard against al-Qaida reprisals, it was in Algeria that the prediction was borne out.

There has been a long-standing rebellion in the north of Mali among the country's Tuaregs, desert nomads who have long resented living under a state run by southerners. Following periodic uprisings, Mali's balance of power shifted decisively in 2011. At that time, a mercenary force that had fought for deposed Libyan leader Moammar Gaddafi returned to Mali, well trained and heavily armed. Meanwhile, a local Islamist militia, as well as a couple of remnants of a 1990s Islamist rebellion in Algeria that claimed to be regional units of al-Qaida, had taken up residence in northern Mali.

Last year, fearing that Mali's fragile democratic government was not up to the challenge of restoring order, some army officers pulled off a coup in Bamako, the country's capital. It was a spectacular failure. The government was overthrown, but the divided army virtually collapsed. The rebels exploited the vacuum to advance further south. Although a nationalist Tuareg militia led the advance, the Islamist forces edged them aside. They created a so-called caliphate in the north, imposing a harsh version of shari'a.

FAILED AMERICAN STRATEGY

The West, anxious to forestall the creation of another al-Qaida base, faced a new reality. The US administration had been trying to avoid an overt military conflict in a region in which it has little presence. Instead, it sent in special forces to train elite units of the Malian army. When some of those recruits then defected to the Islamists and an American-trained officer led the coup, its strategy was in tatters.

So, with the rebels pressing south, France, Mali's former colonial master, reluctantly stepped in. Flying over Algeria, they bombed Malian rebel bases and sent troops in for a ground offensive. The Elysees had been awaiting the mobilisation of a West African force that was scheduled to intervene later this year. But this force is taking longer to organise than hoped.

Meanwhile, the Malian army is barely ready to fight. French President François Hollande apparently judged that if someone didn't take immediate action, the Islamists could advance all the way to Bamako.

For now, reports from the city suggest the French intervention is popular. After all, Islamists have been cutting off hands and banning music in the north - which in Mali, is akin to banning dances in Jamaica.

Nevertheless, France is stepping into a potential minefield. Many northerners would like to send the Islamists packing. But they wouldn't necessarily welcome a reoccupation by southern forces. Besides, given the ethnic and linguistic differences between Tuaregs and southerners, there may be some axes to grind.

EMBROILED IN CONFLICT

The risk of France finding itself in the middle of a civil conflict is now present. Finally, when the ground offensive takes off, French troops will confront foes who know the landscape well, and are skilled at guerrilla tactics.

Within days of the French intervention, rebels allied to one of the four groups operating in northern Mali captured a gas installation in southern Algeria. While they claimed to be punishing the Algerian government for allowing the French to fly through Algerian airspace, the short time lag between the French actions and the hostage-taking suggests a possible coincidence. A raid of such complexity likely took weeks, if not months, to plan, and its leader probably just exploited the coincidence to make a political claim. His own goal, after all, is the overthrow of the Algeria government, not a war in Mali.

Nevertheless, the danger of the conflict widening to the region has been made abundantly clear. Mr Hollande may have felt he had no choice but to act. But he almost certainly did so with an anxious feeling.

John Rapley, a political economist at the University of Cambridge, is currently on a visiting professorship at Queen's University in Canada. Email feedback to columns@gleanerjm.com and jr603@cam.ac.uk