Chapter 8 explores the application of international law and norms in cyberspace. It examines law that governs use of force in international politics, the types of weapons that can be developed and used in armed conflict, how combatants engage in conflict on the battlefield, and when individuals can be held criminally accountable for violating these rules. Some governments classify a cyber operation as equivalent to a use of force or form of warfare only if it produces physical destruction or death, while others declare a cyber operation to be an attack when the targeted system loses its ability to function. Finally, the chapter considers how to develop and encourage the adoption of cyberspace norms for governmental behavior and set expectations for states to regulate illicit cyber activity within their borders.