Updated August 12, 2020
Defense Primer: Naval Forces
“Naval Forces” Refers to Both the Navy
The Navy’s aircraft carriers embark multimission carrier air
and Marine Corps
wings (CVWs) consisting of 60+ aircraft—mostly fixed-
Although the term “naval forces” is often used to refer
wing aircraft, plus a few helicopters. Each CVW typically
specifically to Navy forces, it more properly refers to both
includes 40 or more strike fighters that are capable of air-to-
Navy and Marine Corps forces, because both the Navy and
ground (strike) and air-to-air (fighter) combat operations.
Marine Corps are naval services. For further discussion, see
“Defense Primer: Department of the Navy.” For a
Size of the Navy
discussion of the Marine Corps that focuses on its
The total number of ships in the Navy is a one-dimensional
organization as a ground-combat force, see CRS In Focus
metric that leaves out many other important factors bearing
IF10571, Defense Primer: Organization of U.S. Ground
on naval capability. Notwithstanding this limitation,
Forces, by Barbara Salazar Torreon and Andrew Feickert.
observers often cite the total number of ships in the U.S.
Navy as a convenient way of summarizing the Navy’s
U.S. Strategy and Naval Forces
U.S. naval forces give the United States the ability to
convert the world’s oceans—a global commons that covers
The quoted number of ships in the Navy reflects the battle
more than two-thirds of the planet’s surface—into a
force ships counting method, which is a set of rules for
medium of maneuver and operations for projecting U.S.
which ships count (or do not count) toward the quoted
power ashore and otherwise defending U.S. interests around
number of ships. The battle force ships counting method
the world. The ability to use the world’s oceans in this
was established in the early 1980s and has been modified
manner—and to deny other countries the use of the world’s
by legislation in recent years. Essentially, it includes ships
oceans for taking actions against U.S. interests—constitutes
that are readily deployable overseas, and which contribute
an immense asymmetric advantage for the United States.
to the Navy’s overseas combat capability. The Naval
History and Heritage Command maintains a database on
As discussed elsewhere (see “Defense Primer: Geography,
numbers of ships in the Navy from 1886 to the present. (It
Strategy, and U.S. Force Design), the size and composition
is available here: https://www.history.navy.mil/research/
of U.S. naval forces reflect the position of the United States
histories/ship-histories/us-ship-force-levels.html.) Since this
as a Western Hemisphere power with a goal of preventing
database extends back to 1886, it uses a different counting
the emergence of regional hegemons in Eurasia. As a result,
method that is more suitable for working with older
the U.S. Navy includes significant numbers of aircraft
historical data. This alternate counting method, however,
carriers, nuclear-powered attack submarines, large surface
produces, for the 1980s onwards, figures for the total size of
combatants, large amphibious ships, and underway
the Navy that are different than the figures produced by the
replenishment ships.
battle force ships counting method. For this reason, using
figures from the NHHC database to quote the size of the
Navy Ship Types
Navy in recent years can cause confusion.
The Navy’s ballistic missile submarines (SSBNs) are
dedicated to performing a singular mission of strategic
Navy Force-Level Goal
nuclear deterrence. The Navy’s other ships, which are
The Navy determines its force-level goal—the size and
sometimes referred to as the Navy’s general-purpose ships,
composition of the fleet it would like to reach and maintain
are generally multimission ships capable of performing a
in coming years—through a Force Structure Analysis
variety of missions other than strategic nuclear deterrence.
(FSA). FSAs are conducted every few years. For each type
The principal types of general-purpose ships in the Navy
of ship, the FSA calculates the number required for
include attack submarines (SSNs); aircraft carriers
warfighting, and the number required for maintaining day-
(CVNs); large surface combatants, meaning cruisers
to-day forward-deployed presence overseas. Navy officials
(CGs) and destroyers (DDGs); small surface combatants,
then work with these two calculations to select a final
meaning frigates (FFGs), Littoral Combat Ships (LCSs),
required number for each ship type. The Navy’s current
patrol craft (PCs), and mine warfare (MIW) ships;
force-level goal, released in December 2016, is to reach and
amphibious ships, whose primary function is to transport
maintain a fleet of 355 battle force ships, including 66
Marines and their equipment and supplies to distant
SSNs, 12 CVNs, 104 large surface combatants, 52 smaller
operating areas and support Marine ship-to-shore
surface combatants, and 38 amphibious ships. Section 1025
movements and Marine operations ashore; combat logistics
of the FY2018 National Defense Authorization Act (H.R.
force (CLF) ships, which perform underway replenishment
2810/P.L. 115-91 of December 12, 2017) states “It shall be
(UNREP) operations, meaning the at-sea resupply of
the policy of the United States to have available, as soon as
combat ships; and other support ships of various types.
practicable, not fewer than 355 battle force ships,
comprised of the optimal mix of platforms, with funding
subject to the availability of appropriations or other funds.”

Defense Primer: Naval Forces
Actual Size of the Navy
the waters around Europe. At any given moment, roughly
The size of the Navy in recent years has generally ranged
30% or more of the Navy, including two or three CSGs and
between 270 and 300 battle force ships. As of August 11,
two or three ARGs, might be forward-deployed. Having
2020, the figure was 298. In its FY2021 budget submission,
enough ships to maintain these forward deployments is a
the Navy projects that at the end of FY2021, the Navy
major influence on calculations that determine the Navy’s
would include 306 ships.
force-level goal.
Nuclear-Powered Ships
The forward-deployed presence of Navy ships is intended
The Navy’s submarines and aircraft carriers are all nuclear
to support a number of ongoing or potential missions,
powered, meaning that they use on-board nuclear reactors
including deterrence of potential aggressors; reassurance of
to generate power for propulsion and for running shipboard
allies and partners; engagement operations with foreign
equipment. Navy submarines each have one reactor; Navy
naval and other military forces (which can strengthen
aircraft carriers each have two. All other Navy ships are
political bonds and improve interoperability between the
conventionally powered, meaning that they burn petroleum-
Navy and those other forces); intelligence, surveillance, and
based fuels for propulsion and shipboard power.
reconnaissance (ISR) operations; rapid response in
humanitarian assistance/disaster response (HA/DR)
Navy Nuclear Weapons
situations; non-combatant evacuation operations (NEOs);
The Navy maintains a neither-confirm-nor-deny (NCND)
counter-terrorist operations, crisis response and
policy regarding the presence or absence of nuclear
containment, and timely initial actions during the early (and
weapons on specific ships. In general, however, it is
potentially critical) stages of a conflict.
understood that the only Navy ships that carry nuclear
weapons are SSBNs, which carry nuclear-armed
Forward-Homeported Ships
submarine-launched ballistic missiles (SLBMs). All of the
Most of the Navy’s ships are homeported in the United
Navy’s other nuclear weapons, which were referred to
States. To help support its ability to maintain its forward-
collectively as non-strategic naval nuclear weapons, were
deployed presence, some Navy ships are homeported in
withdrawn from the fleet as part of a unilateral initiative
forward locations. The Navy’s largest forward-homeporting
announced by President George H.W. Bush at the end of
location is Japan, where a CSG, an ARG, and some mine
the Cold War in 1991.
warfare ships are homeported. Additional Navy ships are
forward-homeported elsewhere in the Pacific, in the Persian
Navy Formations
Gulf (at Bahrain), and in or near the Mediterranean (in
Naval forces are modular and scalable—Navy ships can be
Spain and Italy).
combined into formations of various types and sizes that are
tailored for their intended missions. The two most
Relevant Statutes
prominent types of naval formations are carrier strike
groups (CSGs)
and amphibious ready groups (ARGs).
Title 10, U.S. Code, Subtitle C – Navy and Marine Corps
The composition of a CSG can vary, but typically includes
a CVN with its embarked CVW, perhaps three to five

surface combatants (typically one cruiser, plus some
destroyers), a CLF ship, and perhaps an SSN. An ARG
CRS Products
typically includes three amphibious ships—one LHA/LHD
CRS Report RL32665, Navy Force Structure and Shipbuilding
type “big deck” amphibious assault ship (which resembles a
Plans: Background and Issues for Congress, by Ronald O'Rourke
medium-sized aircraft carrier) and two smaller (but still
sizeable) amphibious ships known as LPDs and LSDs. An

ARG typically embarks a Marine Expeditionary Unit
Other Resources
(MEU), which includes more than 2,000 Marines and their
equipment (including some aircraft) and supplies. A third
Congressional Budget Office, The U.S. Military’s Force Structure:
type of naval formation is a Surface Action Group (SAG),
A Primer, July 2016, particularly Chapter 3 (pp. 45-79)
which consists of a few or several surface combatants,
Department of the Navy, Highlights of the Department of the
without an aircraft carrier.
Navy FY 2021 Budget, accessed March 17, 2020, at
Navy ships sometimes operate by themselves—all SSBNs
and many SSNs operate this way, as do some surface
U.S. Navy Program Guide 2017, accessed March 17, 2020, at
combatants and amphibious ships that are deployed to
http://www.navy.mil/strategic/npg17.pdf. (The 2017 edition of
lower-threat areas (such as South America or parts of
this program guide is the most recent edition available.)
Africa) for purposes of engaging with allied or partner
forces in those areas.

Forward-Deployed Operations
The U.S. Navy is unique among the world’s navies in that,
Ronald O'Rourke, Specialist in Naval Affairs
at any given moment, a sizeable fraction of the Navy is
forward-deployed to distant operating areas, particularly the
Western Pacific, the Indian Ocean/Persian Gulf region, and


Defense Primer: Naval Forces

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