Increased existential threats demand that Western Democracies and their armed forces can swiftly scale up, rapidly expanding their capabilities to deter potential adversaries and defend borders effectively. The principle of scaling also applies to crisis response systems in general; the larger the disaster scope, the more crucial scalability becomes to alleviate suffering. From a multidisciplinary viewpoint, this book introduces fresh insights into the concept of scaling by examining scalability within security contexts. This book is structured in three parts. The first part, explores historical perspectives, demonstrating that scaling is deeply rooted in military policy, strategy and practices. The second part, ""Organising Scalability,"" highlights innovative methods and empirical examples of scaling. The final part, ""Enabling Scalability,"" outlines essential resources and popular support to implement scalability. The conclusion presents a new definition and structured process model of scalability. It emphasizes that establishing and organising scalable organizations is complex but feasible. However, it poses a critical question: is our social fabric robust enough to support scaling and are we prepared to defend our core values if war and crises come?