As the drawdown in defense spending starts to take effect, the Department of Defense's ability to maintain the readiness of its military forces is the subject of growing debate. Both civil and military leaders express deep-seated concerns about the impact on national security of defense cuts imposed by the Budget Control Act of 2011 and the March 1, 2013 sequestration. In the past, policy makers have tended to over correct with military drawdowns, thereby paving the way for military missteps. United States policies and defense strategies have historically left the military unprepared for the next conflict following drawdowns. The trajectory of defense spending since 9/11 is fiscally unsustainable despite an ever changing environment that is less secure, as a major drawdown of defense force structure is on the horizon. President Barack Obama warned that "we can't afford to repeat the mistakes that have been made in the past - after World War II, after Vietnam - when our military was left ill-prepared for the future." The question remains is how to accomplish this drawdown without hollowing the force. The purpose of this thesis is to illustrate through case study analysis relevant historical insights from past post-war military drawdowns that should be applied to current budget decisions in order not to end up with a "hollow force" incapable of executing the National Security Strategy. The author concludes that historical lessons from past postwar drawdowns provide a framework for planning the U.S. force structure of the 21st Century.

"12 June 2013"--Thesis approval page.

Introduction. Origins of the hollow force -- Defining the current problem -- Objective and scope / Framing the issue. Overview -- Post-World War II strategy and policy conundrum -- Truman's unexpected conflict -- New Look -- The opportunity cost of defense spending -- Intervention in Indochina -- Flexible response -- Vietnam and defense policy -- Post-Vietnam downsizing -- Cold War buildup -- The Reagan buildup -- Post-Cold War transition -- Post-Cold War -- Global War on Terror and beyond / Approaches to planning the future force. Overview -- Strategic guidance -- Force planning -- Alternative approaches to force planning -- Strategic outlook in planning the future force / Analysis. National interests -- The role of the economy in U.S. national security -- US defense spending -- Procurement holiday -- The cost of maintaining an aging force -- Trade-off between defense, entitlements, and interest payments -- Unsustainable growth in the operations and support accounts -- Tying security strategy to the US role in the global economy / Recommendations and conclusions. Recommendation one: publish a hybrid of NSC 68 & NSC 162/2 for Twenty-First Century -- Recommendation two: know that the next war the U.S. will fight will probably not be the one it was preparing to fight -- Recommendation three: strategic approach to force planning -- Recommendation four: fiscally informed force modernization -- Conclusion.