https://crsreports.congress.gov
Updated December 6, 2022
Defense Primer: Commanding U.S. Military Operations
Military operations, both in peacetime and in war, are an
inherently complex undertaking. One key to success,
therefore, is a clear, unified chain of command. This
enables senior leaders in the U.S. government—in
particular, the President and the Secretary of Defense—to
command and control military forces around the world.
A (Very) Brief History of the Chain of Command
The way the United States commands and controls its
forces is in large part a product of an inherent tension
between improving the effectiveness of U.S. forces, on the
one hand, and preserving civilian control of the military, on
the other. The experience of World War II convinced
President Truman, among others, that a greater degree of
coordination and integration between the U.S. military
services was necessary to improve the conduct of military
operations. Yet there was concern at the time that
integrating these institutions might result in an overly
powerful military staff element that could threaten the
principle of civilian control of U.S. forces.
The resulting compromise was to create a Joint Chiefs of
Staff (JCS), comprising all the military service chiefs, and
headed by a Chairman serving as an advisory body only. As
a corporate body, the JCS was specifically not designed to
exercise command; the Chairman of the Joint Chiefs of
Staff (CJCS) had no command authority. The JCS did,
however, have responsibility for establishing “unified
combatant commands,” which were charged with executing
military operations in different parts of the world by
combining the capabilities of two or more military services.
Different service chiefs were assigned executive and
administrative responsibilities for these combatant
commands, which gave them a mechanism through which
they could influence ongoing military operations. By 1953,
the authority to establish Combatant Commands
(COCOMs) was assigned to the Secretary of Defense,
although the relative ambiguity of the chain of command
remained a feature of Department of Defense (DOD)
operations until 1986.
Perceived shortcomings in the U.S. chain of command led
to demonstrable failures during several incidents in the late
1970s and early 1980s. The military services, in the view of
many observers, failed to effectively plan or conduct
operations jointly due to confusion over whether the
military services or unified combatant commanders were
ultimately in charge of operations. These incidents included
the 1983 operation in Grenada; the 1980 Iranian hostage
rescue attempt (officially “Operation Eagle Claw” but often
called “Desert One”); and the 1983 bombing of the Marine
Barracks in Beirut, Lebanon. In 1986, Congress passed the
Goldwater-Nichols Defense Reform Act (P.L. 99-433),
which mandated clarifications to the chain of command.
The current command and control architecture for DOD is a
product of these congressionally mandated changes.
The Chain of Command
Title 10 U.S.C. §162 specifies that the chain of command
for military operations goes from the President, to the
Secretary of Defense, to Commanders of Combatant
Commands. The Chairman of the Joint Chiefs of Staff acts
as an intermediary, transmitting orders between the
Secretary of Defense and the Commanders of Combatant
Commands. Each Combatant Commander is a four-star
Flag or General Officer, whose appointment is confirmed
by the Senate.
Unified Command Plan (UCP)
The UCP is a classified executive branch document that
articulates how DOD assigns responsibility for different
missions and areas of the world. It is prepared by the
Chairman of the Joint Chiefs of Staff every two years and
approved by the President. Each UCP sets forth basic
guidance to all unified combatant commanders; establishes
their missions, responsibilities, and force structure;
delineates the general geographical area of responsibility
for geographic combatant commanders; and specifies
functional responsibilities for functional combatant
commanders. Congress is not included in this review
process but does have visibility into issues affecting UCP
development. It is through the UCP that DOD develops its
global map of areas of responsibilities for its Combatant
Commanders, reflected in Figure 1.
Figure 1. Combatant Commanders’ Area of
Responsibility
Source: Association of the U.S. Army, “The Army on Point: A
Detailed Summary of Current Operations and Responsibilities
(2022),” August 5, 2022. Accessed November 28, 2022,
https://www.ausa.org/publications/army-point-detailed-summary-
current-operations-and-responsibilities-2022.
