The Accepted Laws of Nations were the unwritten rules of conduct between Safeholdian realms. Often this began with diplomacy and concluded with warfare, on an escalating scale of violence.
During the high level discussions in the Empire of Charis, over how to respond to the seizure of vessels, and the Ferayd Massacre, it was brought up that the Accepted Laws of Nations dictated that either a written protest, or a similar diplomatic solution be tried. However the level of violence brought upon unarmed civilians, required a much stronger response. (BSRA)