Threat-agnostic resilience: Framing and applications

Critical infrastructure is not indestructible. Interdependencies between infrastructure systems and the environment compound consequences at vulnerable locations but can be harnessed to maximize operational efficiency, recovery capability, and long-term sustainability. Threats, both emergent and systemic, have propagated beyond historical norms, exposing the limitations of hazard-specific resilience approaches. These approaches, by their nature, rely on predefined scenarios that fail to capture the full complexity of cascading failures, novel threat combinations, and the dynamic evolution of risks over time, especially in the cases where environment is affected. This leaves critical gaps in planning, response, and recovery, as systems designed around specific hazards are often unable to adapt to disruptions that fall outside their narrowly defined parameters, resulting in unanticipated vulnerabilities and slower recovery trajectories. We propose a paradigm shift toward threat-agnostic resilience, emphasizing adaptability to unforeseen hazards through modularity, distributedness, diversity, and plasticity. These principles foster system-wide robustness by enabling critical functions to persist despite unpredictable challenges. This framework also accounts for the interdependencies between resilience strategies and environmental outcomes, ensuring that adaptability to unforeseen hazards is balanced with sustainability goals. Resilience characteristics, such as modular design and distributed systems, shape patterns of resource use, energy efficiency, and ecological impacts across systems. By identifying methods to assess and optimize these trade-offs, we provide actionable insights for designing infrastructure that simultaneously enhances resilience and minimizes environmental burdens. Challenges exist in developing methodological foundations for these principles within practical applications to prevent sunk cost and over-constraining operational procedures.