This white paper discusses the role of C5ISRT (Command, Control, Communications, Computers, Cyber, Intelligence, Surveillance, Reconnaissance, and Targeting) in shaping the future of Canadian defence. It outlines the current security environment characterized by geopolitical tensions, technological advancements, and state-on-state competition. The paper emphasizes the need for operational readiness that transcends geographic boundaries and involves multiple domains, including land, air, maritime, cyber, and space. It explains how a sovereign C5ISRT system is vital for Canada to assert Arctic sovereignty and maintain interoperability with allies while ensuring that operations are conducted effectively and efficiently. The document details the importance of integrating systems and data to enhance decision-making processes and operational capabilities. Furthermore, it addresses the challenges posed by modern warfare and the necessity for continuous defence readiness, particularly in the Arctic, which is a critical area for Canadian national security. The role of Calian as a systems integrator for C5ISRT capabilities is also presented within the context of strengthening Canada's defence posture.