Quarter.

This is coolbert:

To what extent this is a violation, if any, of the Laws of Land Warfare I am not sure.

Denying quarter to the enemy? Is that what this is?

As it was in Drogheda [1649] so is it now in Raqqa [2017]?

First from the Associated Press:

 1. "Foreigners who joined ISIS faced almost certain death in Raqqa"

"PARIS –  The forces fighting the remnants of the Islamic State group in Syria have tacit instructions on dealing with the foreigners who joined the extremist group by the thousands: Kill them on the battlefield."

Tacit as unwritten but understood by all!! 

And from the Warfare History Network and the article by Al Hemingway:

2. "No Quarter at Drogheda"

Drogheda, The English Civil War. The New Model Army of Cromwell denying quarter to the foe.

"In 1649, at Drogheda, Cromwell’s men stormed hotly into the city. 'No quarter!' they cried."

THE FRENCH APPEAR TO BE PARTICULARLY KEEN ON NOT ALLOWING JIHADISTS, FRENCH-BORN, NATURALIZED OR MERE LEGAL RESIDENTS, TO RETURN. PROBABLY WITH GOOD REASON!

coolbert.