This research considers the implications and role of parliamentarians in applying the approach of Common Security. In an insecure context, traditional state-centric security models fail to maintain a secure world, even if they are on the rise. The concept of common security, with at its core the principle that no nation can achieve safety at the expense of others, offers a sustainable alternative. However, to achieve this, structural shifts are required - mainly in the redefinition of the security narrative: What does security mean, for whom, and how is it achieved? In this vision, parliamentarians, through their functions (legislative, oversight, budgetary, representative, and diplomatic), are uniquely positioned to drive this shift at both national and international levels. 

Through the insights of three case studies - parliamentary diplomacy efforts, how different parliamentary functions can promote nuclear disarmament, and a practical analysis of the security issues in the West African region- as well as semi-structured interviews with experts and members of parliaments, this research proposes key findings. Namely: a newly expanded definition of common security, building on the intellectual and historical foundations of the concept and adapted to today’s international challenges; a grid designed to operationalise common security for parliamentarians, bridging the gap between theoretical principles and everyday parliamentary practice; and a set of practical recommendations for MPs according to the specific functions identified. This analysis demonstrates that common security is far more than a theoretical concept - it is a practical lens for action that can be implemented through the diverse parliamentary functions. The possibilities emphasised by the experts and parliamentarians in the interviews make it clear that parliamentarians can play a central role in shaping security policy strategies.