Contemporary military networks and the requirements arising from future strategic planning, call for the increasing integration of information mobility and network enabled capabilities on the field. Therefore, adopting Service Oriented Architecture (SOA) concepts for the development of command and control infrastructures have become essential, since they provide modularity, flexibility and interoperability of services. Nevertheless, constraints related to infrastructure and operational aspects, render current enterprise SOA ineffective for the tactical domain. Accordingly, the goal of TACTICS was the definition and experimental demonstration of a Tactical Services Infrastructure (TSI) that enables contemporary tactical radio equipment to participate in SOA, providing the required functionalities under the imposed constraints. This article presents a comprehensive view of the developed architecture, focusing on the elements that constitute the security framework according to our closing experimental results and field demonstrations.