key input. These threats can be understood and modeled only when we identify and understand the societal environment, the geopolitical dynamics within which the terrorist networks are energized and operate, and the characteristics and limitations of the threatened infrastructure. The causal relationships among these inputs and outputs then enable the building of models that predict the efficacy of risk-management policy options.

Understanding counterterrorism as a “system of systems” is essential, because the outputs of the terrorism network, as shown in Figure 10.1, are the same four types of risk that constitute the inputs to the homeland security system. Terrorism network characteristics, the resulting potential sources of risk, and homeland infrastructure and security characteristics all contribute to the comprehensive effort needed to identify conceivable types of risk. Additional characteristics, such as the funding sources of the terrorist groups, the level of sophistication of these groups, and the driving forces that feed them (such as unfavorable socioeconomic conditions, geopolitical considerations, cultural conflicts, and racial and religious issues), are also essential to the risk analysis.

Four major risk classes to homeland security can be identified, as shown in Figure 10.1:

  1. Risks to human lives and to individual property, liberty, and freedom;

  2. Risks to organizational and societal infrastructures and to the continuity of government operations, including the military and intelligence-gathering infrastructure;

  3. Risks to critical cyber and physical infrastructures; and

  4. Risks to socioeconomic sectors.

An essential factor for sound decision making is identification of these and other sources of homeland risk at a sufficient level of detail. This will enable effective strategic and tactical planning.


While systems engineering is essential to the successful design, development, and deployment of a complex system (Sage and Rouse, 1999), how well a system is operated once it is deployed is the concern of systems management.

The new Office of Homeland Security (OHS) is developing a strategic plan for the United States that will include the participation of many public and private organizations. To support the development of its plan, the OHS will need an overall management system that takes into account many of the governance, decision-making, and information systems and tools discussed below.

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