A submersible (abbreviated sub) is a vessel that can operate entirely submerged. Marine archaeology, facility inspection and maintenance, and salvage and exploration are only some of the civilian applications of submarines.
As a nuclear strike force, submarines undertake various critical military roles, including striking enemy watercraft above and below the surface, guarding allied aircraft carriers and other vessels, and conducting blockade runs, surveillance, and other activities.

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Modern Military Submarine Fleets
The primary purpose of today’s submarine fleets, whether big or small, is to serve as a deterrence inside a nation’s borders. Ballistic missile submarines, assault submarines, & cruise missile submarines are various kinds of submarines used by the United States Navy.
Global Fire Power states that each nation’s submarine fleet is always monitored.
Submarines are uncommon in nations without permanent armed forces. GFP did not include such nations in its rankings. The rankings are also aggregate totals and do not consider the type, size, age, military purpose, or build quality of each submarine in the rankings.
Global Firepower 2021’s top 10 list of countries with the largest military submarine fleets include:
- China – 79
- United States – 68
- Russia – 64
- North Korea – 36
- Iran – 29
- South Korea – 22
- Japan – 20
- India – 17
- Turkey – 12
- Colombia, Greece, United Kingdom (tie) – 11
Despite this, the GFP list varies greatly from a comparable rating by the International Institute of Strategic Studies (IISS) that was produced in 2021 as well.
According to IISS 2021, these are the 10 countries with the largest military submarine fleets:
- North Korea – 71
- United States – 68
- China – 59
- Russia – 49
- Japan – 22
- South Korea – 18
- Iran – 17
- India – 16
- Turkey – 12
- Greece, United Kingdom (tie) – 11
Both lists are shown in detail in the table at the end of this page.

Throughout history, the military has used submarines
On September 7, 1776, a submersible was first used in battle during the American Revolutionary War. On that day, an effort was made in New York Harbor to attach a bomb to a British Royal Navy warship using an eight-foot-long hand-powered sub named the Turtle.
Due to the early stages of submarine technology, the endeavor failed. Submarine combat efforts were restricted in this and many other battles, despite several novels’ attempts to submarine architecture.
On the other hand, Submarines would only be widely used in the military during World War I, some 130 years after their invention.
Also See: Nuclear Weapons by Country 2022
Submarines were proven to be a potent and lethal weapon during World War II. By destroying commercial ships, Germany destroyed Britain’s supply line.
This was the most diversified submarine fleet in World War II, ranging from midget submarines to medium-range submarines to long-range fleets of submarines. Japan also launched the most modern torpedoes, the quickest submarines, and the subs that could carry numerous planes.
These are the 10 countries with the most submarines:
- China (79)
- United States (68)
- Russia (64)
- North Korea (36)
- Iran (29)
- South Korea (22)
- Japan (20)
- India (17)
- Turkey (12)
- United Kingdom (11)
Country | # Submarines (GFP) | # Submarines (Al Jazeera) |
---|---|---|
China | 79 | 59 |
United States | 68 | 68 |
Russia | 64 | 49 |
North Korea | 36 | 71 |
Iran | 29 | 17 |
South Korea | 22 | 18 |
Japan | 20 | 22 |
India | 17 | 16 |
Turkey | 12 | 12 |
United Kingdom | 11 | 11 |
Colombia | 11 | 4 |
Greece | 11 | 11 |
France | 10 | 8 |
Pakistan | 9 | 8 |
Egypt | 8 | 7 |
Italy | 8 | 8 |
Algeria | 8 | 6 |
Brazil | 6 | 5 |
Vietnam | 6 | 8 |
Germany | 6 | 6 |
Australia | 6 | 6 |
Norway | 6 | 6 |
Indonesia | 5 | 4 |
Peru | 5 | 6 |
Sweden | 5 | 5 |
Israel | 5 | 5 |
Canada | 4 | 4 |
Taiwan | 4 | 4 |
Chile | 4 | 4 |
Netherlands | 4 | 4 |
Azerbaijan | 4 | |
South Africa | 3 | 2 |
Poland | 3 | 3 |
Bangladesh | 2 | 2 |
Spain | 2 | 2 |
Argentina | 2 | 1 |
Malaysia | 2 | 2 |
Venezuela | 2 | 1 |
Ecuador | 2 | 2 |
Portugal | 2 | 2 |
Myanmar | 1 | 1 |
Cuba | 1 | |
Singapore | 4 |