Military installations face the threats that afflict modern societies, such as natural hazards, resource unavailability, and the failure of technology, yet their military mission requires the installations to maintain their functionality in the face of these threats. The compounding of risk, however, makes the maintenance of functionality even more difficult and unpredictable. Compounding risks result from threats which interact and trigger additional events that thereby heighten the threat to functionality of physical infrastructure. Currently, for the purposes of risk management, the potential impacts of a threat are often assessed for specific scenarios. In these scenarios, both the threat and system vulnerability are specified, which necessarily but inadvertently excludes many plausible unspecified compound threat scenarios. As a result, risk management solutions often address a limited number of threats and vulnerabilities, are confined to a limited number technology areas, and tend to primarily focus on assessing and hardening individual components of complex systems under a specific threat scenario. This approach can be costly across environmental, economic, and societal domains while still missing the compounding events risk.
While efforts have long existed to understand and prepare for extreme events driven by single causes, less is known about how systems can be resilient to compounding events risk. Compounding events cannot currently be sufficiently or practically addressed by traditional risk assessment and mitigation approaches. When a high degree of interdependence among systems is observed, the underlying systemic risk is difficult to characterize since the pathways that can cause impact (i.e., vulnerabilities) to complex systems move along multiple pathways. Perhaps an approach more tractable than adopting specific safeguards for specific events may be to develop systems and structures for rapid and efficient recovery of mission critical functions following disruption without regard of the combination of events that might occur. To determine the validity of this hypothesis, research is needed to examine how and to what extent DoD installations and other infrastructure systems might frame the risk of disruption from compound events and the ability of installations to recover and adapt mission critical functions. In addition, other hypotheses may provide fruitful lines of discovery and may be proposed as research foci.
Prior and existing initiatives at the DoD have examined aspects of resilience and compounding events risk; nonetheless, a distinct gap remains in understanding how to consider installation resilience to compound events risk. Risk-based approaches have been applied to the problem of addressing vulnerabilities in these systems, through methods such as mapping the interaction of threats, identifying vulnerabilities to multiple types of events, and conducting “red team” analyses for various assets and facilities; each has their weaknesses. In addition, historically applied statistical and probabilistic frameworks appear to have limited utility in light of uncertainty and increasing complexity.