The current controversy is whether Geneva Conventions apply to terrorists, especially since terrorism has no universally agreed-upon definition
Background
As long as there has been conflict, man has tried to devise ways to limit wartime behavior, from the sixth century BCE Chinese warrior Sun Tzu to the 19th century American Civil War.The founder of the International Red Cross, Henri Dunant, inspired the first Geneva Convention, which was designed to protect the sick and wounded. Pioneer nurse Clara Barton was instrumental in U.S. ratification of that First Convention in 1882.
Subsequent Conventions addressed asphyxiating gases, expanding bullets, the treatment of prisoners of war, and treatment of civilians. Nearly 200 countries -- including the United States -- are "signatory" nations and have ratified these Conventions.