French overseas territories are very dependent on oil. Unlike in France proper, most of their electricity is produced by diesel generators. Nearly everything has to be imported and the tourism sector is highly dependent on the continued availability of a reasonably cheap air transport.
As the age of cheap and abundant energy comes to an end, France, and presumably The Netherlands and Britain as well, will be less and less able to afford those imperial leftovers at the other side of the world. At some point of the future, they will have to get rid of them, and violence is very likely to be a part of the equation.