Cyberwar is gaining recognition as a “fifth battlefield”. It is also becoming evident that a well-organized Computer Network Attack (CNA) may harm Norway’s vital infrastructure. This project proposes to examine the legal challenges that arise with respect to the development of effective international and national strategies to prevent, regulate and resolve cyberwar. How can we develop legal mechanisms and procedures that allow for cyber security threats to be properly assessed? Which legal considerations and constraints should shape the development of civilian cybersecurity institutions? In creating a legal regime for Cyberwarfare, what dilemmas arise?