China has ramped up production of nuclear submarines over the past five years and is launching them faster than the United States, threatening to negate the sea power advantage that has long belonged to the United States, a new think tank report says.
The People’s Liberation Army Navy’s nuclear submarine fleet includes both ballistic missile submarines and attack submarines, according to a report by the International Institute for Strategic Studies (IISS).
Between 2021 and 2025, China’s submarine construction exceeded that of the United States in both number of submarines launched (from 10 to seven) and tonnage (from 79,000 tons to 55,500), the report said. The report looked at satellite images of shipyards to estimate China’s construction status.
The Chinese government has not disclosed the number of vehicles it owns.
This is a significant turnaround from 2016 to 2020, when China added only three submarines (23,000 tons) to the U.S. Navy’s seven submarines (55,500 tons), according to an IISS analysis.
This number represents submarines launched but not necessarily completed and added to the active fleet, in which the United States still maintains a significant advantage.
According to IISS’s Military Balance 2025, as of early 2025, China had 12 active nuclear submarines, six ballistic missile boats, and six guided missile or attack craft. The United States has a total of 65 submarines, 14 of which are equipped with ballistic missiles.
According to the Military Balance, China also maintains a fleet of 46 large conventionally powered submarines.
The United States does not have conventionally powered submarines that, unlike nuclear submarines, require regular refueling.
The report, titled “Boosting in Bohai,” said the Chinese government has significantly expanded Bohai Shipbuilding Heavy Industries’ Hudao yard in northern China to accommodate the growing nuclear submarine fleet.
This comes after a Congressional Research Service report submitted to Congress last month found that the U.S. Navy is falling well short of its annual submarine construction goal of two Virginia-class attack boats, with U.S. shipyards delivering only 1.1 to 1.2 submarines per year starting in 2022.
The United States is also building a new Columbia-class ballistic missile submarine, but that program is at least a year behind schedule, with the largest ship, the USS District of Columbia, not scheduled to be delivered to the Navy until 2028, the admiral in charge of the program told Breaking Defense last week.
“Increasing marine populations are becoming a growing challenge as (the United States and other Western) countries struggle to increase their own production,” the IISS report said.
The IISS report focuses on two Type 094 ballistic missile submarines (SSBNs) launched at the Wulu Island Shipyard. Capable of launching nuclear-tipped ballistic missiles, the Type 094 joins Beijing’s growing nuclear triad of land-based intercontinental ballistic missiles and bombers, the newspaper said.
And China is developing an even better SSBN, the IISS says.
“Type-096 is still expected to enter production in Bohai this decade and enter service in the late 2020s or early 2030s,” the paper said.
In addition to SSBNs, the PLA Navy’s nuclear launch numbers over the past five years have included the hulls of at least six guided missile submarines (SSGNs), according to the report. These boats are equipped with vertical launch systems (VLS) that could be used to launch new high-speed anti-ship missiles that were unveiled at China’s Victory Day parade in Beijing last fall.
But the IISS report isn’t all bad news for Washington and its allies.
“Chinese designs are almost certainly lagging behind U.S. and European vessels in terms of quality,” the report said.
China’s most advanced submarines are not believed to be as quiet as their American counterparts, leaving the stealth advantage to the U.S. Navy.
Still, experts say larger forces usually win in naval battles. And China already has the world’s largest fleet of destroyers, frigates, and surface combatants.
Meanwhile, Washington is struggling to catch up.
Secretary of the Navy John Phelan told a House hearing last summer that U.S. naval construction was in dire straits.
“All of our programs are a mess,” Phelan said.
“I think our best plan is six months late and 57 percent over budget…that’s the best plan,” he testified.
As for the number of submarines over the next five years, a Congressional Research Service (CRS) report says the number of U.S. attack submarines is expected to reach a “trough” of 47 in 2030 as the aging Los Angeles-class attack craft is retired.
An increase to 50 attack submarines is not planned until 2032 if construction targets are met, the report said. However, the paper notes that plans to sell three to five Virginia-class submarines to Australia as part of the AUKUS deal could hamper plans to expand the US fleet in the short term.
The CRS report said the upcoming submarine force “trough” was first noted in 1995 and added that it “could result in a period of increased operational tension for SSN forces and perhaps a period of weakened conventional deterrence against potential adversaries such as China.”
