Former French hostage Serge Lazarevic arrived home on Wednesday, welcomed by President François Hollande. The 51-year-old was held for three years with another Frenchman who was subsequently shot dead by his captors. But even before Serge Lazarevic landed, the controversy had begun, with reports of Islamist militants freed in exchange in Mali and elsewhere. Paris insists it did not pay, so what was the trade-off and what fallout could there be from such a deal?
