April 18, 2019
U.S. War Costs, Casualties, and Personnel Levels Since 9/11
Seventeen years have passed since the U.S. initiated major
military operations following the September 11, 2001,
terrorist attacks. In the intervening period, operations first
classified as Global War on Terror (GWOT) and later
Overseas Contingency Operations (OCO) have varied in
scope. Though primarily focused on locations in
Afghanistan and Iraq, they have also included territories
throughout Central and Southeastern Asia, the Middle East,
and Africa. This In Focus summarizes major expenditures
on U.S. war operations, reconstruction assistance, troop
levels and casualties, and ongoing issues for Congress. This
analysis narrowly defines war/non-war costs as OCO-
designated appropriated funds associated with overseas
operations as designated in DOD’s official “Cost of War
(CoW)” report. Other observers may define war operations
or costs more broadly (see “Issues for Congress” section).
Department of Defense War Costs
Congress has appropriated a total of $1.55 trillion in
discretionary amounts to the Department of Defense (DOD)
for war funding since 9/11, according to DOD reporting.
(See following section for OCO non-war expenditures.)
Obligations of those amounts peaked during two surges of
U.S. military activity; first in Iraq in FY2008 ($140 billion),
and then in Afghanistan in FY2011 ($97 billion).
Figure 1. Iraq and Afghanistan: War Spending and
Troop Levels Since 2008
Source: For costs, DOD “Cost of War,” September 2018; for troop
levels, FY2020 DOD Comptroller “Defense Budget Request
Overview.”
As a percentage of total OCO-designated obligations, the
two conflicts have been roughly equivalent. Obligations for
operations primarily in Afghanistan represent 49% ($737
billion) overall, while those for Iraq represent 51% ($759
billion).
Over the past three years, obligations for war spending have
averaged $47 billion per year, mostly to fund the operating
support costs of U.S. forces in and around Afghanistan.
Between FY2016-FY2018, the Afghan Security Forces
Fund comprised 9.16% of all obligations for Afghanistan.
In Iraq and Syria, obligations for war fell with the departure
of most U.S. troops in December 2011, but rose again as air
and ground operations against ISIS intensified. Between
FY2016 and FY2018, the U.S. obligated an average of $7.2
billion annually for operations in Iraq and Syria.
DOD Non-War Program Costs
According to DOD reporting, roughly 12% ($.2 trillion) of
all funding appropriated through war-related requests since
9/11 has funded non-war programs. These include
congressional transfers to OCO, funding for the European
Deterrence Initiative, non-DOD classified programs,
adjustments for (non-GWOT) fuel costs, and Army
modularity programs (service restructuring).
Use of the OCO Designation
Estimates of the cumulative costs of war are complicated by
the use of OCO-designated funds for base budget activities.
Under current law, funding designated for emergencies and
overseas contingencies is not counted under budget limits
set annually by congressional budget resolutions. After
passage of the Budget Control Act (BCA) in 2011,
exceeding such budget caps triggers across-the-board cuts
(sequestration) to agency programs.
As a means of complying with the BCA, Congress and the
president have increasingly designated substantial amounts
of funding as OCO to provide for base military activities.
Because of this practice, some argue that OCO has become
a slush fund that obscures the true cost of both war and non-
war spending. Others argue that the OCO designation
affords necessary flexibility to apply funds when and where
needed.
Base and Enduring Requirements
DOD’s FY2020 budget request debuts new OCO funding
categories that identify the requirement for which the
portion of OCO is intended. These requirement categories
include the following:
Direct War Requirements ($25.4 billion; 15%):
Direct combat support and partnership training costs.
OCO for Enduring Requirements ($41.3 billion;
24%): Indirect operational costs likely to remain even
after GWOT combat operations have ended; also funds
European Deterrence Initiative and Ukraine Security
Assistance.
OCO for Base Requirements ($97.9 billion; 56%):
Base funding included to comply with BCA spending
limits.
Emergency Requirements ($9.2 billion; 5%):
Includes $2 billion in disaster relief and $7.2 billion
intended for construction of southwest border wall.
