Since 2001, the Department of Defense (DoD) has regularly requested large appropriations to supplement its base-budget funding. Most of that nonbase funding has been designated for overseas contingency operations (OCO) that began after 9/11. CBO examined how DoD’s use of OCO funding has affected its spending. Growth of Funding. Between 1970 and 2000, nonbase funding accounted for about 2 percent of DoD’s total spending. Since 2001, such funding has accounted for a much larger and persistent share of annual defense appropriations. Amounts of Funding. Nonbase funding peaked at 28 percent of DoD’s budget in 2007 and 2008. From 2001 to 2018, it has averaged about $116 billion per year (in 2019 dollars), totaling about 20 percent of DoD’s total funding. Funding for Enduring Activities. In CBO’s estimation, from 2006 to 2018, more than $50 billion in OCO funding per year (in 2019 dollars), on average, has gone toward the costs of enduring activities rather than the temporary costs of overseas operations. DoD’s most recent budget request indicates that, beginning in 2019, the department plans to increase the base budget to include most of that enduring funding in future years. Presentation by F. Matthew Woodward, an analyst in CBO’s National Security Division, at a joint seminar by the Congressional Research Service, the Congressional Budget Office, and the Government Accountability Office.

1. Congressional Budget Office
A Joint Seminar by the Congressional Research Service, the Congressional
Budget Office, and the Government Accountability Office
March 7, 2019
F. Matthew Woodward
National Security Division
Overseas Contingency Operations:
Trends and Issues

2. 1
CBO
The Congressional Budget Office

3. 2
CBO
CBO supports the Congressional budget process by providing the Congress with
objective, nonpartisan, and timely analyses of legislative proposals and of
budgetary and economic issues.
CBO’s Role

4. 3
CBO
Historical Perspective on Funding for
Overseas Contingency Operations
(OCO)

5. 4
CBO
GWOT = Global War on Terrorism.
Base-Budget and Nonbase Funding for DoD, 1950 to 2019
In addition to its regular, base-
budget request for funding, the
Department of Defense (DoD)
requests nonbase funds for
unanticipated expenses.
Before 2001, that practice was
limited. After 2001, OCO were
funded one year at a time with
nonbase budgets.

6. 5
CBO
Nonbase Funding and
Enduring Operations

7. 6
CBO
In the initial phases of a contingency operation, it can be difficult to predict costs.
However, that changes over time:
 The operating costs of a large deployed force become relatively predictable,
because it is difficult to rapidly change the force’s size once it is deployed, and
 New patterns in the size and kinds of U.S. forces operating in a part of the
world begin to emerge.
Enduring activities are the elements of contingency operations that have
become routine. Their costs can be expected to change little from budget to
budget.
Evolution of Contingency Operations

8. 7
CBO
Data for forces dedicated to in-theater support are not available for years before 2009.
Average Numbers of Operational Forces in Iraq and Afghanistan
and In-Theater Support Forces, 2006 to 2019
Despite a sharp decrease in the
number of operational forces, the
number of in-theater support forces
has changed little.

9. 8
CBO
Data on the cost of in-theater support are not available for years before 2013.
OCO Funding for Operations and In-Theater Support, 2006 to 2019
Funding for in-theater support has
remained relatively constant since
2013 despite a decrease in funding
for operational forces.

10. 9
CBO
In CBO’s estimation, from 2006 to 2018, more than $50 billion in OCO funding
per year (in 2019 dollars), on average, has gone toward the costs of enduring
activities rather than the temporary costs of overseas operations.
DoD’s fiscal year 2019 budget request indicated that, beginning in 2019, the
department planned to increase the base budget to include most of what it
considered enduring funding in future years.
Funding for Enduring Activities

11. 10
CBO
Effects of Incorporating Enduring
OCO Funding in the Base Budget

12. 11
CBO
a. DoD’s base budget plus CBO’s estimate of enduring OCO funding. Projected values are based on DoD’s 2019 Future Years Defense Program.
The Possible Effect of Moving Enduring OCO Funding Into
DoD’s Base Budget
Including the projected costs of
enduring activities in the base
budget (as reported in the
President’s 2019 budget request)
would increase it by about $47
billion per year starting in 2020.

13. 12
CBO
a. The adjusted base budget includes DoD’s base budget plus contingency-related funding in the OCO budget starting in 2006. CBO could not identify such spending in earlier years
because DoD did not categorize OCO funding by function or mission until 2006. Projected values are based on DoD’s 2019 Future Years Defense Program.
How DoD’s Base-Budget Funding Would Look If It Included
All OCO-Related Funding, 1950 to 2019
0
300
600
900
1950 1960 1970 1980 1990 2000 2010 2020
Total Budget
Base Budget
Adjusted
Base Budgeta
Billions of 2019 Dollars
Funding long-term, large-scale
operations in the OCO budget rather
than the base budget tends to
understate the actual costs of
implementing U.S. national security
strategy and foreign policy.
Furthermore, the practice of funding
overseas conflicts outside of the
base budget departs from historical
norms.
The adjusted base budget in the
figure is constructed to be more
consistent with trends in DoD’s
funding before 2001.