Mojo is correct- sadly it seems that bombing Syria and Iraq isn't really a strategy that can be entirely effective: all of the actors are born and raised in France. For me the root causes are at home, as are the solutions: schools, sports, jobs and anything that can help connect our Muslim youth to the rest of society.
At least one was posing as a syrian refugee, possibly from another middle eastern country. There are several ways to win this fight, easily too - it just "costs" too much.
1. Level Raqqa / Syria into a parking lot [Cost: Losing Position of the righteous, "humanity"]
2. 250,000 american boots on the ground [Cost: American lives]
Unfortunately Daesh has been abusing the migrant flow and integrated actors within the groups of refugees with fake passports, stolen passports, cover stories, and i'm sure there are many many more cells in France, UK, Sweden and most certainly Germany. the USA / Canada have an advantage have having a nice water gap and can heavily screen refugees, but Canada has already been hit by 2 lone wolf terrorist attacks, and i fear more will follow.
There's no way to "win" without losing. We are in for a few interesting years.