It is a rite of passage for every new French president to head to French-speaking Africa and reaffirm faith in la Francophonie. So it was with Francois Hollande, who has just visited Senegal and the Democratic Republic of Congo. Like his predecessor, Nicolas Sarkozy, he said “francafrique”—the cosy post-colonial ties of party financing, arms, contracts and influence—was over and that human rights were paramount. He praised the shared use of French, “language of liberty”. But behind the warm words lie grimmer concerns, the biggest being the entrenchment of terror networks in the al-Qaeda-held Sahel.

Despite France’s reluctance to play post-colonial gendarme, Mr Hollande is starting to sound tougher on Mali. During his African trip, he tried to rally regional leaders to the cause. Manuel Valls, the interior minister, visited Algeria to narrow differences. France drafted a UN Security Council resolution, unanimously adopted on October 12th, that authorises the dispatch of an African force to retake rebel-held territory in Mali. Jean-Yves Le Drian, the French defence minister, says such a force could be ready “within weeks”.

Yet his enthusiasm may be overdone. The plan is that a force would be made up of troops from Mali and other countries in the Economic Community of West African States (ECOWAS). But, even if willing ones can be lined up, regional forces do not have the capacity to mount an offensive operation without logistical and intelligence support. The French are ready to contribute, but have ruled out sending in ground troops. Although the European Union says it will send trainers under an EU flag, the Americans are reluctant to get involved.

France’s anxiety is that, if nothing is done, the Sahel might become a crucible for Islamist terrorism. “What makes people very nervous is the idea that it will become Africa’s Afghanistan,” says Francois Heisbourg of the Foundation for Strategic Research, a think-tank. France, with its colonial history and commercial ties, is an obvious target. One Malian Islamist group has explicitly threatened Mr Hollande since his push for military action, and said that French hostages are in greater danger.

As it is, France is already fretting about terrorist threats. Although there is no direct link to AQIM, French police dismantled an Islamist cell in France earlier this month, arresting 12 suspects and shooting one dead. Two were wanted in connection with an attack on a kosher grocer in a Paris suburb last month, which rattled France’s big Jewish population. Seven have been charged with terrorist offences.

Francois Molins, the Paris public prosecutor, called the cell “extremely dangerous”. Some suspects were French converts to Islam. The threat is “increasingly coming from within”, Mr Valls told the Senate, adding that radicalisation can take a matter of months. The country was shocked earlier this year when seven people, including three Jewish children and a rabbi, were shot dead in Toulouse by a French Islamist who claimed to have been trained by al-Qaeda. The surveillance of radicals has been stepped up. Mr Valls is putting a law before parliament to give the police new powers to pursue French nationals abroad suspected of links to terrorism or of attending foreign training camps. With or without a French-backed operation in Mali, France is on high alert.