The French military has escalated its intervention in Mali.
It has put some 2,000 troops on the ground since airstrikes failed to halt Islamist forces there.
France has direct economic interests in the region. It gets much of the uranium to feed its nuclear power stations from neighbouring Niger.
Major uranium deposits have recently been found in northern Mali.
Jean-Yves Le Drian said France was engaged in the “total reconquest” of Mali.
The British media is reporting that the British military is on alert to deploy alongside French forces.
The government has not openly made any such commitment. But it says it will step up logistical and transport support.
The rest of the sabre rattling is more likely to be down to resistance to cuts in the armed forces.
The French and British governments have played up the threat to their interests in the region.
Cameron says that Islamic rebels offer European powers an “existential threat”.
Despite—or because of—its close military connections with regimes in the area, the US has been noticeably less keen to take this line.
When asked if this was a threat to the US, defence secretary Leon Panetta said “probably not”.
This is not down to any squeamishness about violent military engagements. US drones killed at least eight people in Yemen on Saturday of last week.
African regimes in the region are moving to deploy troops.
Further Western or African military intervention can only accelerate the spread of the conflict.
Two soldiers in the Nigerian contingent were killed when a roadside bomb exploded by their convoy on the way to Mali last Saturday.
The rebellion in northern Mali was among the Tuareg people.
Up to three million of them are spread between Mali, Niger, Algeria, Libya and other neighbouring countries.
There are about 800,000 Tuareg in Mali and there have been five rebellions since independence.