Cyber war is real and is being waged. Cyber terrorists and cyber warriors are attacking systems, but fortunately, they are attacking systems in much the same way hackers attack systems. This is good for system security designers as the security controls installed to protect against hacking will work to protect against cyber terrorists and warriors. However, while there are several tools that can be used to identify security requirements including checklists, threat and risk analysis, and security policies, these methods are not integrated into an overall design methodology that can be used to ensure that security requirements are identified and then implemented. This chapter proposes using barrier analysis and the concept of defense in depth to modify Siponen and Baskerville’s (2001) integrated design paradigm that is more graphical and easier to understand and use methodology that is expected to improve security to be built into systems and improve defenses against cyber warfare.