Section 347 of the 2012 National Defense Authorization Act called on the Department of Defense to commission an independent assessment of the overseas basing presence of U.S. military forces. As the recipient of that commission, RAND's National Defense Research Institute conducted an independent assessment of the advisability of changes in the overseas basing presence of U.S. forces based on an evaluation of strategic benefits, risks, and costs. The report characterizes how overseas presence contributes to assurance of allies, deterrence, contingency responsiveness, and security cooperation, along with the risks involved with investing in facilities overseas. It breaks new ground in the understanding of the costs associated with overseas presence, including how permanent and rotational presence costs compare, and provides cost models for policymakers to weigh alternative posture options. To support this understanding of costs the report also lays out the conditions of U.S. installations and levels of host nation support. The report concludes that there are certain minimum requirements necessary to carry out the current national security strategy, but it is prudent, based upon the net value produced, to maintain an overseas posture that goes beyond these minimums. Additionally, it combines benefit, cost, and risk considerations to distill a number of strategic judgments that have implications for the advisability of considering identified posture changes.

"Prepared for the Office of the Secretary of Defense"--T.p.

Introduction. Purpose -- Approach -- Brief history of the U.S. global posture -- The current U.S. global posture -- How this report is organized / Strategic considerations: benefits of overseas posture to contingency response. Force types and implications for deployment and presence -- Small-scale contingency deployment analysis -- Direct operational support -- Implications for posture / Strategic considerations: benefits of overseas posture for deterrence and assurance. The role of foreign posture in deterring potential foes -- Assuring allies -- Implications for posture / Strategic considerations: benefits of overseas posture for security cooperation. Does overseas basing provide cost advantages for security cooperation? -- Does overseas basing improve partner willingness to deploy forces? -- Does overseas basing provide benefits for partner capability development? -- Does overseas basing provide training advantages for U.S. forces? -- How do rotational forces change U.S. military strategies for security cooperation? -- Implications for posture / Risks to investing in facilities overseas. Political risks to access -- Changing operational risks to posture -- Assessing violent extremist risks to posture -- Implications for posture / Installation conditions. Data on installation conditions -- Findings on installation conditions -- Implications of findings on installation quality for postures / Host-nation support and U.S. payments to other countries. Terminology and data sources -- Lessons from historical data -- Analysis of contemporary data on host-nation support and U.S. Payments -- NATO security investment program contributions -- Host-nation support data collection in the future -- Implications of findings on host-nation support and U.S. payments for postures / Relative costs of overseas basing and rotational presence. Introduction to cost analysis -- Recurring permanent presence cost analysis -- Rotation cost analysis -- Investment cost methodology -- Implications for posture / Illustrative postures. Parameters of all illustrative postures -- Elements of current U.S. posture that are held constant -- Illustrative cost-reduction posture -- Illustrative global responsiveness and engagement posture -- Illustrative major contingency posture -- Summary of posture changes / Analysis of illustrative postures. Recap of the common features of the illustrative postures -- Deployment responsiveness -- Availability of basing for direct operational support -- Deterrence and assurance -- Security cooperation -- Risks to U.S. installations -- cost comparisons of illustrative postures -- Implications for determining actual postures / Conclusions. Minimal essential posture needs -- Regional considerations -- Value perceptions and priorities are critical to posture decisions / Appendix A: cost analysis appendix -- Appendix B: detailed cost analysis results -- Appendix C: security cooperation cost differential between forward-based and U.S.-based forces -- Appendix D: U.S. military overseas prepositioned equipment -- Appendix E: deployment analysis scenario APOD and APOE details -- Appendix F: USFJ-related costs borne by Japan -- Appendix G: analysis of missile threat to bases for the postures -- Appendix H: detailed estimates of host nation contributions from Japan, South Korea, and Germany -- Appendix I: summary tables of illustrative postures.