The obvious weakness of the French and their distraction with events elsewhere in the region emboldened the amirs to demand and secure the reinstatement of the coutume .
Scientific expeditions into Mauritania became increasingly subject to attack , and their European leaders were killed or held for ransom .
The obvious weakness of the French and leaders ' distraction with events elsewhere in the region emboldened the amirs to demand and secure the reinstatement of the coutume .
Scientific expeditions into Mauritania became increasingly subject to attack , and their European leaders were killed or held for ransom .