Over recent years the depth to which we have grown to rely on networked computer systems as part of the critical national infrastructure has become ever more apparent. Concern over difficulties caused by accidental failures has led to a realisation of the potential for damage that could be caused by targeted attacks and cyber warfare. Current approaches to addressing these problems have tended to focus on traditional security measures, and have not mobilised the full breadth of capabilities provided by digital technologies. In this paper we will explore some of the challenges associated with these developments. We also consider potential solutions, and in particular how a combination of networking, security, advanced gaming, visualisation techniques, and the increasingly blurred boundary between physical and digital entities, can be used to improve protection of critical infrastructure systems.