Nicolas Henin was held hostage by Daesh for seven months. Kept in an underground cell alongside executed American journalist James Foley, he says he was physically and psychologically abused by, among others, the infamous Jihadi John.
Released after intense negotiations, Henin has his own theories about will and will not work in the fight against Daesh.
"We are just fueling our enemies and fueling the misery and disaster for the local people," he said in an interview with The Syria Campaign, referring to coalition airstrikes, adding that "strikes on ISIS are a trap."
"The winner of this war will not be the party that has the newest, the most expensive or the most sophisticated weaponry, but the party that manages to win over the people on its side."
He also pointed to the refugee crisis. The West’s refusal to assist the legitimate Syrian government of Bashar al-Assad is chiefly responsible for the wave of people fleeing their homes in Syria. Henin praised the efforts of countries which have welcomed the refugees, saying that is one of the effective ways of fighting the terrorist group.
"Hundreds of thousands of refugees, fleeing this Muslim land that is like a dream for ISIS – that is supposed to be their Israel? And fleeing that land to go to the land of the 'unbelievers'?" he said.
"This is why they probably tried to manipulate the public during the Paris attacks," Henin added. "To make us close our borders, and maybe even more importantly, close our minds."
But heated anti-refugee rhetoric in Europe and the United States threatens to play into the hands of the terrorist group.
Henin’s statements came ahead of the British Parliament’s decision to approve airstrikes in Syria. Royal Air Force jets began a bombing campaign mere hours after the vote.
On Friday, Germany’s lower house of parliament also voted to provide air support to French efforts in the bombing campaign.
"What we have to do – and this is really key – is we have to engage the local people. As soon as the people have hope for a political solution, the Islamic State will just collapse," Henin said.
"Why are we making so many mistakes? Why are people so misunderstanding [Daesh’s] vision?" according to Reuters. "They understand each other very well."