On November 26, 2008, the Project on National Security Reform submitted its 2-year study of the national security system, Forging a New Shield, to the President, Presidentelect, and Congress. The study found that the national security system was at risk of failure and needed serious reform. Before the Project finalized the report's recommendations, its Vision Working Group tested the findings against a diverse set of scenarios to determine if the recommendations were robust and effective. This testing revealed that each of the five major findings improved the performance of the current national security system. This volume documents the scenario-testing process used by the Vision Working Group. It includes the actual pre-reform and post-reform scenarios and details many other scenario techniques used in the overall study. The work of the Vision Working Group has led to the formulation of another recommendation: The country must establish a mechanism to infuse greater foresight into the Executive Branch, and in particular the national security system. This proposed mechanism, named the Center for Strategic Analysis and Assessment, would exist and operate within the Executive Office of the President. This volume details the proposed architecture and operation of the Center. The Project on National Security Reform advocates establishment of such a foresight mechanism as part of the larger transformation of the national security system and is ready and willing to assist in its implementation.