This article examines a set of problems for assessing the resilience of lifeline systems under extreme conditions, including threat models, vulnerability identification, and recovery. The advantages and disadvantages of topological and flow models for identifying such vulnerabilities are described. The key objectives of a strategy for restoring damaged network infrastructure components are highlighted. An analysis of the resilience of a lifeline system under extreme conditions is conducted, based on changes in performance at different stages of its operation (absorption, impact assessment, recovery, and adaptation). Stages of studying the resilience of lifeline systems are proposed, which are used in simulation.