Cyber warfare presents new challenges to western governments and private organizations. The gravest danger posed on western governments is a strategic threat on their central information infrastructure, which necessitates the development of new approaches to effectively respond to such cyber challenges. This manuscript discusses the main stream American and Russian approaches to cyber warfare based on official documents, briefings and relevant research. The manuscript then identifies the cyber challenges Israel faces and offers a response by recognizing the lessons provided by the US and Russian approaches. The manuscript analyzes the US and Russian Approaches to Cyber Security according three parameters: Cyber Security definition and its place in the National Security Concept; Doctrinal & Practical Basis for Cyber Security and a legal basis for Cyber Security.