This report presents the context for and decision support requirements in the field of critical infrastructure protection. The author then examines alternatives in structuring ‘Levels of Cooperation’ and concludes that we need to distinguish at least between operational coordination and coordination in the development of measures and capabilities for critical infrastructure protection. Next the report presents a critical account of the experience of Bulgaria both in operational and development coordination. In the concluding section the author recommends to focus not only on centralized, top-down decision making, but to explore the benefits of bottom-up approaches and accelerate the implementation of tools like exchange of experience, testing interoperability, conducting joint, multi-agency, multi-stakeholder training and exercises, benchmarking, and to provide for free flows of information and knowledge, as well as continuous learning. This will serve to identify and prove certain promising concepts and contribute to the development of a culture of cooperation.