You dont want them in French Guiana, thats where the launch base is !
Devils Island is all tourist now, and the old prison at st. laurent du maroni is a museum. But they still have the guillotine on display....
The first thing the French need to do is what Netherlands has done and say “No Jihadis allowed back in the country if they go fight in Syria/Iraq/Yemen and anywhere else”. (I think I have this right, Netherlands brought up the legislation at least)