The analysis of CBRN terrorism risks is a national priority and a DHS imperative. To enable such analysis, requires tools that facilitate decision making based on identified risks. The tools available address risk assessment but not risk management. Furthermore, these tools do not model intelligent adversaries when conducting threat/risk assessment. This SBIR is concerned with developing and implementing a prototype decision analysis methodology for CBRN Terrorism Risk Analysis that overcomes these limitations. The methodology is intended to support Weapons of Mass Destruction (WMD) medical countermeasure decision making. The proposed approach augments Probabilistic Risk Analysis with simpler decision-analytic approaches for both risk assessment and risk management, and incorporates an intelligent adversarial model within its threat representation. Phase I of this effort is concerned with producing a functional prototype for CBRN Terrorism Risk Analysis that can be implemented and available on standard personal computers.Anticipated Benefits/Potential Applications. The overall methodology is expected to become part of strategic planning tools used in government and industry. Potential applications include cyber network infrastructure protection, business continuity planning, and counter-insurgency operations planning.