This paper offers a decision making process based on terrorism risk. The purpose of the model is to support effective decision making in order to involve multiple potential targets and countermeasure alternatives. Because of the complexity of the issues and the posible catastrophic consequences of a terrorist attack, it is necesary to use an analytical tool to detect, assess, warn, response, and recovery the critical infrastructure. The perspective taken is that in order to establish priorities for threats and vulnerabilities and to identify and evaluate options for action.