Updated October 10, 2023
Defense Primer: Naval Forces
“Naval Forces” Refers to Both the Navy
(UNREP) operations, meaning the at-sea resupply of
and Marine Corps
combat ships; and other support ships of various types.
Although the term naval forces is often used to refer
specifically to Navy forces, it more properly refers to both
The Navy’s aircraft carriers embark multimission carrier air
Navy and Marine Corps forces, because both the Navy and
wings (CVWs) consisting of 60+ aircraft—mostly fixed-
Marine Corps are naval services. For further discussion, see
wing aircraft, plus a few helicopters. Each CVW typically
CRS In Focus IF10484, Defense Primer: Department of the
includes 40 or more strike fighters that are capable of air-to-
Navy, by Ronald O'Rourke. For a discussion of the Marine
ground (strike) and air-to-air (fighter) combat operations.
Corps that focuses on its organization as a ground-combat
force, see CRS In Focus IF10571, Defense Primer:
Size of the Navy
Organization of U.S. Ground Forces, by Barbara Salazar
The total number of ships in the Navy is a one-dimensional
Torreon and Andrew Feickert.
metric that leaves out many other important factors bearing
on the Navy’s size and capabilities. Even so, observers
U.S. Strategy and Naval Forces
often cite the total number of ships in the U.S. Navy as a
U.S. naval forces give the United States the ability to
convenient way of summarizing the Navy’s size and
convert the world’s oceans—a global commons that covers
capabilities.
more than two-thirds of the planet’s surface—into a
medium of maneuver and operations for projecting U.S.
The quoted number of ships in the Navy reflects the battle
power ashore and otherwise defending U.S. interests around
force ships counting method, which is a set of rules for
the world. The ability to use the world’s oceans in this
which ships count (or do not count) toward the quoted
manner—and to deny other countries the use of the world’s
number of ships in the Navy. The battle force ships
oceans for taking actions against U.S. interests—constitutes
counting method was established in the early 1980s and has
an immense asymmetric advantage for the United States.
been modified by subsequent legislation. Essentially, it
includes ships that are readily deployable overseas, and
As discussed elsewhere (see CRS In Focus IF10485,
which contribute to the Navy’s overseas combat capability.
Defense Primer: Geography, Strategy, and U.S. Force
The Naval History and Heritage Command maintains a
Design, by Ronald O'Rourke), the size and composition of
database on numbers of ships in the Navy from 1886 to the
U.S. naval forces reflect the position of the United States as
present. (It is available here: https://www.history.navy.mil/
a Western Hemisphere power with a goal of preventing the
research/histories/ship-histories/us-ship-force-levels.html.)
emergence of regional hegemons (and otherwise defending
Since this database extends back to 1886, it uses a different
and promoting U.S. interests) in Eurasia. As a result, the
counting method that is more suitable for working with
U.S. Navy includes significant numbers of aircraft carriers,
older historical data. This alternate counting method,
nuclear-powered attack submarines, large surface
however, produces, for the 1980s onwards, figures for the
combatants, large amphibious ships, and underway
total size of the Navy that are different than the figures
replenishment ships.
produced by the battle force ships counting method. For this
reason, using figures from the NHHC database to quote the
Navy Ship Types
current size of the Navy 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.
(CGs) and destroyers (DDGs); small surface combatants,
meaning frigates (FFGs), Littoral Combat Ships (LCSs),
In December 2016, the Navy released a force-structure goal
mine warfare (MIW) ships, and patrol craft (PCs);
that calls for achieving and maintaining a fleet of 355 ships
amphibious ships, whose primary function is to transport
of certain types and numbers. The 355-ship goal was made
Marines and their equipment and supplies to distant
U.S. policy by Section 1025 of the FY2018 National
operating areas and support Marine ship-to-shore
Defense Authorization Act (H.R. 2810/P.L. 115-91 of
movements and Marine operations ashore; combat logistics
December 12, 2017). The 355-ship goal predates the Trump
force (CLF) ships, which perform underway replenishment
and Biden Administrations’ national security and national
defense strategies and does not reflect the new fleet
https://crsreports.congress.gov

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Defense Primer: Naval Forces
architecture (i.e., new mix of ships) that the Navy wants to
that are deployed to lower-threat areas (such as South
shift toward in coming years. This new fleet architecture is
America or parts of Africa) for purposes of engaging with
to feature, among other things, a significant number of large
allied or partner forces in those areas.
unmanned vehicles (UVs). The Navy and the Department
of Defense (DOD) have been working since 2019 to
Forward-Deployed Operations
develop a successor for the 355-ship force-level goal that
The U.S. Navy is unique among the world’s navies in that,
would reflect current national defense strategy and the new
at any given moment, a sizeable fraction of the Navy is
fleet architecture. On July 18, 2023, it was reported by
forward-deployed to distant operating areas, particularly the
USNI News that the Navy on June 20, 2023, had submitted
Western Pacific, the Indian Ocean/Persian Gulf region, and
to Congress a classified, congressionally mandated report
the waters around Europe. At any given moment, as much
on a new Battle Force Ship Assessment and Requirement
as 30% of the Navy, including up to two or three CSGs and
(BFSAR) that reportedly calls for achieving a future fleet of
up to two or three ARGs, might be forward-deployed.
381 ships, including 31 larger amphibious ships.
Having enough ships to maintain these forward
deployments is a major influence on calculations that
Current Size of the Navy
determine the Navy’s force-level goal.
The size of the Navy in recent years has generally ranged
between 270 and 300 battle force ships. As of October 5,
The forward-deployed presence of Navy ships is intended
2023, the figure was 290.
to support a number of ongoing or potential missions,
including deterrence of potential aggressors; reassurance of
Nuclear-Powered Ships
allies and partners; engagement operations with foreign
The Navy’s submarines and aircraft carriers are all nuclear
naval and other military forces (which can strengthen
powered, meaning that they use on-board nuclear reactors
political bonds and improve interoperability between the
to generate power for propulsion and for running shipboard
Navy and those other forces); intelligence, surveillance, and
equipment. Navy submarines each have one reactor; Navy
reconnaissance (ISR) operations; rapid response in
aircraft carriers each have two. All other Navy ships are
humanitarian assistance/disaster response (HA/DR)
conventionally powered, meaning that they burn petroleum-
situations; noncombatant evacuation operations (NEOs);
based fuels for propulsion and shipboard power.
counter-terrorist operations, crisis response and
containment, and timely initial actions during the early (and
Navy Nuclear Weapons
potentially critical) stages of a conflict.
The Navy maintains a neither-confirm-nor-deny (NCND)
policy regarding the presence or absence of nuclear
Forward-Homeported Ships
weapons on specific ships. In general, however, it is
Most of the Navy’s ships are homeported in the United
understood that the only Navy ships that carry nuclear
States. To help support its ability to maintain its forward-
weapons are SSBNs, which carry nuclear-armed
deployed presence, some Navy ships are homeported in
submarine-launched ballistic missiles (SLBMs). All of the
forward locations. The Navy’s largest forward-homeporting
Navy’s other nuclear weapons, which were referred to
location is Japan, where a CSG, an ARG, and some mine
collectively as nonstrategic naval nuclear weapons, were
warfare ships are homeported. Additional Navy ships are
withdrawn from the fleet as part of a unilateral initiative
forward-homeported elsewhere in the Pacific, in the Persian
announced by President George H.W. Bush at the end of
Gulf (mostly at Bahrain), and in or near the Mediterranean
the Cold War in 1991.
(mostly in Spain and Italy).
Navy Formations
Relevant Statutes
Naval forces are modular and scalable—Navy ships can be
combined into formations of various types and sizes that are
Title 10, U.S. Code, Subtitle C – Navy and Marine Corps
tailored for their intended missions. The two most
prominent types of naval formations are carrier strike

groups (CSGs) and amphibious ready groups (ARGs).
The composition of a CSG can vary, but typically includes
CRS Products
a CVN with its embarked CVW, perhaps three to five
CRS Report RL32665, Navy Force Structure and Shipbuilding
surface combatants (typically one cruiser, plus some
Plans: Background and Issues for Congress, by Ronald O'Rourke
destroyers), a CLF ship, and perhaps an SSN. An ARG
typically includes three amphibious ships—one LHA/LHD

type “big deck” amphibious assault ship (which resembles a
Other Resources
medium-sized aircraft carrier) and two smaller (but still
sizeable) amphibious ships known as LPDs and LSDs. An
Congressional Budget Office, The U.S. Military’s Force Structure:
ARG typically embarks a Marine Expeditionary Unit
A Primer, 2021 Update, May 2021, particularly Chapter 3 (pp.
(MEU), which includes more than 2,000 Marines and their
45-77)
equipment (including some aircraft) and supplies. A third
Department of the Navy, Highlights of the Department of the
type of naval formation is a Surface Action Group (SAG),
Navy FY 2024 Budget, accessed March 23, 2023, at
which consists of a few or several surface combatants,
https://www.secnav.navy.mil/fmc/fmb/Documents/24pres/Highl
without an aircraft carrier. Navy ships sometimes operate
ights_Book.pdf
by themselves—all SSBNs and many SSNs operate this
way, as do some surface combatants and amphibious ships
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Defense Primer: Naval Forces

IF10486
Ronald O'Rourke, Specialist in Naval Affairs


Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
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