The development of "information warfare" presents international legal issues that will complicate nations' efforts both to execute and to respond to certain information warfare attacks, specifically those using computers, telecommunications, or networks to attack adversary information systems. Some legal constraints will certainly apply to information warfare, either because the constraints explicitly regulate particular actions, or because more general principles of international law govern the effects of those actions. Nevertheless, the novelty of certain information warfare techniques may remove them from application of established legal categories. Furthermore, the ability of signals to travel across international networks, and affect systems in distant countries, conflicts with the long-standing principle of national, territorial sovereignty.