Protecting key urban assets, particularly transportation, energy, communication, and critical service infrastructures, is a fundamental requirement of passive defense planning and urban resilience enhancement. Due to the concentration of strategic assets in Sirjan, including the railway network, transport terminals, airport, special economic zone, and sensitive service centers, spatial risk assessment of these assets is of particular importance. This study aims to assess and spatially classify the risk of key urban assets in Sirjan against intentional human-made threats, with emphasis on the terrorist bombing scenario as the base threat. The research is applied in purpose and descriptive–analytical in method. Required data were collected through documentary studies, spatial layers, passive defense documents, and expert questionnaires. The expert panel consisted of 30 specialists in passive defense, urban infrastructure, crisis management, urban planning, and GIS, of whom 28 valid questionnaires were included in the analysis. In the analytical process, asset value, threat level, and vulnerability were calculated based on the FEMA framework, while the weights of the indicators were determined using the Analytic Hierarchy Process. The results were then integrated in a GIS environment to produce a classified spatial risk map. Findings indicate that the terrorist bombing threat, with a score of 7.511, was selected as the base threat. The railway line, transport terminals, railway station, special economic zone, and broadcasting center were classified as very high-risk assets, while the airport, blood transfusion center, and oil storage facility were identified as high-risk assets. The results reveal that risk is mainly concentrated in the city’s transportation and economic assets. Accordingly, passive defense interventions should prioritize access control, physical security enhancement, recovery capacity improvement, and the development of service continuity plans for critical urban assets.