ABSTRACT. The development and application of the information and communications technology has created a new battleground. Cyber security will significantly affect international relations in the 21st century. This paper gives an overview of the concepts and principles of cyber threats that affect the safety and security in an international context. It is shown the state of the art in cyber security risk assessment of Supervisory Control and Data Acquisition (SCADA) systems. The discussion begins with an examination of what constitutes critical national infrastructure and the roles of ICS and SCADA systems within it. The examination also touches on the political and social challenges in achieving greater cyber security, and then shifts to a description of how the US government divides efforts among its lead cyber security agencies and what responses to a cyber attack on ICS or SCADA might look like. The discussion finishes with recommendations for strengthened international consensus on norms for state behavior, formalized public-private relationships, and interagency efforts to realize a more secure and resilient national infrastructure.