	Introduction

After several years of rapid growth in defense budgets, measures to reduce federal budget deficits have led to projections of a substantial decline in military spending over the next decade. As a result of limits on discretionary spending in the Budget Control Act of 2011 ( P.L. 112-25 ), the Department of Defense (DOD) is considering how to absorb a reduction of about $490 billion in planned programs through FY2021. Senior defense officials have said that such reductions can be managed, but they also warn that that trade-offs among defense programs will require a strategically grounded re-assessment of priorities, and deeper cuts would weaken critical capabilities. A common theme is, unless reductions are managed prudently, budget cuts of the magnitude required, let alone larger cuts, would risk creating a hollow force As former Secretary of Defense Robert Gates put it:
I am determined that we not repeat the mistakes of the past, where the budget targets were met mostly by taking a percentage off the top of everything, the simplest and most politically expedient approach both inside the Pentagon and outside of it. Significance for Congress

The Administration has invoked the specter of a hollow force to describe what could happen to the U.S. Armed Forces if significant cuts to the defense budget are enacted. While some Members and staff might be familiar with the hollow force and its causes, newer Members and staff might not have a similar understanding of the conditions that led to the hollow force in the past and what actions were taken to improve the situation. Given the Administration's plan to reduce troop strength in response to budgetary limitations and a new strategic direction, Congress—in its oversight, authorization, and appropriations role—will likely encounter Administration officials who claim that the U.S. military faces the prospect of once again becoming a hollow force As Congress will play a major role in shaping the Armed Forces both in terms of size, capabilities, and how it is equipped and trained, a nuanced understanding of how the military once became "hollow" could provide a useful context for current and anticipated legislative action. Background

			Origins of the Hollow Force

Recent warnings about the need to avoid creating a hollow force evoke two periods in history in which the term was commonly used to characterize the state of the U.S. military—post-Vietnam and the 1990s. New concerns about recruiting and retention also began to emerge. Service in the U.S. Armed Forces during this period was not particularly attractive for a variety of reasons. Reserve forces suffered from the same personnel shortages as did their active duty counterparts, but equipment and training deficiencies were even more pronounced. In this regard, some suggest that DOD and the Army itself also bear a degree of culpability in creating General Meyer's hollow divisions. The use of the term hollow force to describe the effects of the defense budget decline of the 1990s does not appear apt, and certainly not if it is taken to reflect a parallel with the personnel and other readiness-related shortfalls of the 1970s. Current References to Hollow Forces

			Return to a Hollow Force? While the services have suggested that future budget cuts might endanger reset, it should be noted that the services have a great deal of discretion on how operation and maintenance (O&M) funds are allocated and therefore have great influence on how the reset of equipment is conducted. It also is unlikely that even in the case of drastically reduced military funding and a smaller military, recruit quality would decline, pay and benefits would be drastically cut, or U.S. public support for the military would significantly decline.
Senior Department of Defense (DOD) leaders have invoked the specter of a "hollow force" to describe what could happen to the U.S. Armed Forces if significant cuts to the defense budget are enacted. While some Members and staff might be familiar with the hollow force and its causes, newer Members and staff might not have a similar understanding of the conditions that led to the hollow force and what actions were taken to improve the condition of the U.S. Armed Forces.
After several years of rapid growth in defense budgets, measures to reduce federal budget deficits have led to projections of a substantial decline in military spending over the next decade. As a result of limits on discretionary spending in the Budget Control Act of 2011, DOD is considering how to absorb a reduction of $450 billion to $500 billion in planned programs through FY2021. Senior defense officials have said that such reductions can be managed, but they also warn that that trade-offs among defense programs will require a reassessment of priorities, and that deeper cuts would weaken critical capabilities. A common theme is that, unless reductions are managed prudently, budget cuts of the magnitude required, let alone larger cuts, would risk creating a hollow force The term hollow force refers to military forces that appear mission-ready but, upon examination, suffer from shortages of personnel and equipment and from deficiencies in training.
Historically, there were two periods—post-Vietnam and again in the 1990s—when the term hollow force was used to describe the U.S. Armed Forces. In the case of post-Vietnam, a variety of socioeconomic factors as well as funding decisions played a large role in the overall decline in readiness, particularly the decision to develop new weapon systems rather than funding other requirements. The 1990s hollow force, however, did not suffer from the socioeconomic problems that characterized the post-Vietnam force. Instead, the military of the early and mid-1990s was being deployed on a frequent basis for a variety of contingency operations and was viewed by some as being "overcommitted" relative to its size and resources. This overcommitment was further exacerbated by recruiting and retention concerns and a lack of funds to finance new weapon systems due to DOD decisions to emphasize readiness-related funding.
A number of current defense officials have warned about the return to a hollow force if the DOD budget is cut significantly. Other senior officers instead suggest that in the aftermath of two wars, a reduction in the defense budget and the force is not unprecedented and the services will be able to make the necessary adjustments to ensure readiness. Therefore, the question arises if it is fair to suggest that the military could become a hollow force if DOD funding was drastically reduced and if force structure and weapon systems programs were cut. Some believe this is a mischaracterization, as it is considered unlikely the quality of the force will decline, that pay and benefits will be cut to the point that service in the military becomes unattractive, and public support for the military will erode—all factors that lead to General Meyer's description of the post-Vietnam Army as a hollow force It is also noted that DOD has a great deal of discretion on how its funds are spent and how units are organized, manned, equipped, and trained, which is also a factor that contributes to readiness of the force.
As Congress will play a major role in shaping the Armed Forces in terms of size, capabilities, and how it is equipped and trained, a nuanced understanding of how the military once became "hollow" could provide a useful context for current and anticipated legislative action.