Bottom-Up Review

This report, an unclassified version of an earlier classified GAO report, reviews the objectives, methodology, and results of the Pentagon's war game Nimble Dancer, which assessed the ability of the U.S. armed forces to fight and win two nearly simultaneous major regional conflicts. GAO also discusses the assumptions and data used in Nimble Dancer relating to several areas, such as readiness, threat, and force availability. GAO provides its observations on the objectives, methodology, and results of the exercise. It also provides details on specific areas of interest.

GAO found that: (1) DOD statements that Nimble Dancer tested basic Bottom-Up Review assumptions through intensive and extensive war-gaming suggest a more rigorous level of analysis than occurred during the exercise; (2) Nimble Dancer was a useful forum for promoting interaction among DOD organizations and in identifying critical issues in fulfilling the two-MRC requirement; (3) however, Nimble Dancer used many of the same favorable assumptions contained in DOD guidance implementing the Bottom-Up Review; (4) although DOD originally considered examining the sensitivity of certain key assumptions, this type of analysis in some cases was not done, and in other cases its scope was limited; (5) furthermore, DOD did not fully examine the impact of certain critical issues; (6) for example, DOD's analyses of chemical warfare and the extraction of forces from peace operations were limited in scope and did not fully identify the impact of these issues on MRCs; (7) also, DOD deferred detailed analyses of the sufficiency of support forces and intelligence capabilities to other studies; (8) the limited sensitivity analysis of certain key assumptions and limited analysis of some critical issues precluded DOD from analyzing the robustness of the programmed Bottom-Up Review force to meet the two-MRC requirement under more adverse circumstances; (9) in addition, DOD lost opportunities to acquire additional information about the impact of specific critical issues on U.S. capabilities; (10) military judgment is an integral part of any DOD war game or analysis; (11) during Nimble Dancer, DOD relied on the professional military judgment of participants to reach its conclusions, especially where modeling and other analytical results were not available; and (12) all of these factors--favorable assumptions, limited sensitivity analysis, the lack of full analysis of certain critical issues, and heavy reliance on military judgment in some cases where analysis was lacking--should be considered in evaluating DOD's conclusions that Nimble Dancer tested and validated Bottom-Up Review assumptions.