Evaluating the efficiency of multifunctional parks in the resilience of urban critical infrastructure during wartime plays a decisive role in passive defense planning and crisis management, particularly in strategic metropolises such as Ahvaz, which are constantly exposed to military threats; because despite their high multifunctional potential, these spaces are often neglected from the perspective of passive defense, and overlooking their efficiency doubles the vulnerability of urban vital arteries during crises. This study, aiming to evaluate the efficiency of parks in District 3 of Ahvaz during war crises and to identify priorities for enhancing their role in protecting critical infrastructure, employed a mixed-method approach (qualitative-quantitative) utilizing fuzzy Delphi technique, semi-structured interviews, and a researcher-developed questionnaire to identify and localize 53 indicators within four main dimensions: infrastructural-environmental, service-relief, institutional-managerial, and socio-human. The questionnaire was distributed among 500 citizens, managers, and experts in District 3, and the data were analyzed using one-sample t-test, Pearson correlation, and confirmatory factor analysis in SPSS and AMOS software. The findings revealed that all four dimensions have a positive and significant relationship with park efficiency during war crises, with the highest impact attributed to the infrastructural-environmental and socio-human dimensions. The components of voluntary participation and vegetation cover are in a favorable condition, while crisis communication and specialized personnel are at the lowest level. Based on prioritization, five areas—physical strength, spatial positioning, emergency sheltering, crisis communication, and specialized personnel—were identified as the most critical intervention areas with very high priority. The present study, by providing a practical and localized model, takes an effective step in enhancing the resilience of urban critical infrastructure in the face of military threats and outlines a clear vision for urban planning based on passive defense.