The following is the Nov. 15, 2022, Congressional Research Service, Defense Primer: Naval Forces.
From the report
“Naval Forces” Refers to Both the Navy and Marine Corps
Although the term naval forces is often used to refer specifically to Navy forces, it more properly refers to both Navy and Marine Corps forces, because both the Navy and Marine Corps are naval services. For further discussion, see CRS In Focus IF10484, Defense Primer: Department of the Navy, by Ronald O’Rourke. For a discussion of the Marine Corps that focuses on its organization as a ground-combat force, see CRS In Focus IF10571, Defense Primer: Organization of U.S. Ground Forces, by Barbara Salazar Torreon and Andrew Feickert.
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 more than two-thirds of the planet’s surface—into a medium of maneuver and operations for projecting U.S. power ashore and otherwise defending U.S. interests around the world. The ability to use the world’s oceans in this manner—and to deny other countries the use of the world’s oceans for taking actions against U.S. interests—constitutes an immense asymmetric advantage for the United States.
As discussed elsewhere (see CRS In Focus IF10485, Defense Primer: Geography, Strategy, and U.S. Force Design, by Ronald O’Rourke), the size and composition of U.S. naval forces reflect the position of the United States as a Western Hemisphere power with a goal of preventing the emergence of regional hegemons (and otherwise defending and promoting U.S. interests) in Eurasia. As a result, the U.S. Navy includes significant numbers of aircraft carriers, nuclear-powered attack submarines, large surface combatants, large amphibious ships, and underway replenishment ships.
Navy Ship Types
The Navy’s ballistic missile submarines (SSBNs) are dedicated to performing a singular mission of strategic nuclear deterrence. The Navy’s other ships, which are sometimes referred to as the Navy’s general-purpose ships, are generally multimission ships capable of performing a variety of missions other than strategic nuclear deterrence. The principal types of general-purpose ships in the Navy include attack submarines (SSNs); aircraft carriers (CVNs); large surface combatants, meaning cruisers (CGs) and destroyers (DDGs); small surface combatants, meaning frigates (FFGs), Littoral Combat Ships (LCSs), mine warfare (MIW) ships, and patrol craft (PCs); amphibious ships, whose primary function is to transport Marines and their equipment and supplies to distant operating areas and support Marine ship-to-shore movements and Marine operations ashore; combat logistics force (CLF) ships, which perform underway replenishment (UNREP) operations, meaning the at-sea resupply of combat ships; and other support ships of various types.
The Navy’s aircraft carriers embark multimission carrier air wings (CVWs) consisting of 60+ aircraft—mostly fixed-wing aircraft, plus a few helicopters. Each CVW typically includes 40 or more strike fighters that are capable of air-to-ground (strike) and air-to-air (fighter) combat operations.
Size of the Navy
The total number of ships in the Navy is a one-dimensional metric that leaves out many other important factors bearing on the Navy’s size and capabilities. Even so, observers often cite the total number of ships in the U.S. Navy as a convenient way of summarizing the Navy’s size and capabilities.
The quoted number of ships in the Navy reflects the battle force ships counting method, which is a set of rules for which ships count (or do not count) toward the quoted number of ships in the Navy. The battle force ships counting method was established in the early 1980s and has been modified by subsequent legislation. Essentially, it includes ships that are readily deployable overseas, and which contribute to the Navy’s overseas combat capability. The Naval History and Heritage Command maintains a database on numbers of ships in the Navy from 1886 to the present. (It is available here: https://www.history.navy.mil/research/histories/ship-histories/us-ship-force-levels.html.) Since this database extends back to 1886, it uses a different counting method that is more suitable for working with older historical data. This alternate counting method, however, produces, for the 1980s onwards, figures for the total size of the Navy that are different than the figures produced by the battle force ships counting method. For this reason, using figures from the NHHC database to quote the current size of the Navy can cause confusion.
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