This book examines national security telecommunications resilience and threats. Natural disasters, terrorist attacks, or other large-scale incidents can have devastating impacts on the Nation's public and private communications networks and the critical functions they support. The potential for local and national security consequences resulting from a cyber attack or system corruption can be equally devastating to critical infrastructure and key resources. The Federal Government manages or participates in a number of initiatives focused on approving the interoperability and resilience of present-day communications. While it would be near impossible to develop and maintain networks that are invulnerable to disruption, ensuring long-term communications resilience requires that the Government understand future systems and the future technology landscape when investing in and planning for durable, survivable communications.