Charter of the United Nations
Internationally, the United Nations Charter, Article 51, defining self defense, and Article 2\(4\), defining unlawful use of force, together with Chapter VII, outlining allowable activities of the Security Council, are sources for the debate on what is legal behavior for warfighters. There is still some question as to whether these provisions even apply to "information warfare." The Law of Armed Conflict probably does apply, but requires new interpretations of terms, since much of the Law of Armed Conflict predates computers.