WASHINGTON – The United States Navy plans to begin arming submarines in 2024 with ship-targeting versions of the widely used Tomahawk missile, part of Washington’s push to ramp up military capabilities to challenge Chinese maritime forces, particularly around Taiwan.

The Maritime Strike version of the Tomahawk, the missile traditionally used as a ground-attack weapon, will be fielded after Oct 1, programme manager Captain Jon Hersey said in a statement.

The latest models will be modified with a new guidance system enabling them to “engage a mobile target at sea”, he said, adding that the navy took delivery of the initial version in 2022 for tests before declaring it combat ready.

Fielding the new version of the Tomahawk, which made its battlefield debut in the early hours of the 1991 Persian Gulf War in Iraq, would add to a growing US arsenal of ship-attack missiles to complement submarine-launched torpedoes intended to counter China’s numerically superior fleet.

While the US Navy also plans to start fielding the weapons on surface vessels, those are more vulnerable to China’s land- and sea-based anti-ship arsenal.

Taiwan, which China claims as its sovereign territory, is of particular interest to Washington. which sees defending the island – and its crucial semiconductor industry – as a strategic, economic and political priority.

The schedule for the new maritime strike missile fits roughly within the Pentagon’s plans to field thousands of drones in the Indo-Pacific region to counter China, known as the Replicator programme, which the Pentagon aims to deploy on a large scale between February and August 2025.

The development also comes alongside Washington’s burgeoning security alliance with Britain and Australia, known as Aukus. The trio on Dec 1 announced a raft of plans, including the use of artificial intelligence aboard aircraft patrolling the Pacific to help track Chinese submarines.

More work to be ‘war-winning’

The missiles will be deployed on Los Angeles- and Virginia-class submarines, which can carry as many as 12 land-attack Tomahawks, although some modified versions of the Virginia-class will be able to carry as many as 40.

The weapons have a range of up to 1,600km, according to Mr Brent Sadler, a senior research fellow in naval warfare and advanced technology at the Heritage Foundation, as well as a former submariner and head of the navy’s Asia-Pacific advisory group.

“The long range provides greater stand-off from Chinese anti-access and area-denial missile forces, and this would complicate Chinese planning for a blockade/invasion of Taiwan,” Mr Sadler said in an e-mail.

“More work is needed to develop how these missiles will be employed to overwhelm” China’s forces and take out enough ships to be “war-winning”, he said.

Japan may someday also deploy the new anti-ship version of the missile.

The State Department notified Congress in December that Tokyo has been cleared to receive its first ground-attack Tomahawks in a sale valued at as much as US$2.35 billion (S$3.15 billion) for up to 200 missiles.

“Should Japan also get this weapon, it adds another level of complexity the Chinese will have to contend with,” Mr Sadler said.

China has 370 ships and submarines in its naval force, including more than 140 major surface combatants, the Pentagon said in its latest assessment of Chinese military power. The US Navy has 291 deployable vessels.

China’s navy is largely composed of modern multi-mission ships and submarines, and it launched its third aircraft carrier, the CV-18 Fujian, in 2022.

Vice-Admiral William Houston, the navy’s Submarine Forces Commander, said in a statement to Bloomberg News that he is committed to fielding the Maritime Strike Tomahawk as quickly as possible but noted “procurement, modernisation and fielding schedules are dynamic and impacted by a variety of factors, including industrial base and shipyard capacity”.

The US anti-ship arsenal now includes the ship-launched RTX SM-6 air defence missile adapted by the Pentagon’s Strategic Capabilities Office and Lockheed Martin’s long-range anti-ship missile. It can be launched from the Air Force B-1-B bomber and the navy’s top aircraft carrier fighter, the F/A-18 E/F.

Separately, the US Navy also fields Boeing’s sea-skimming Harpoon anti-ship missiles, and Taiwan is buying at least 400 ground-launched versions for coastal defence.

Those types of missiles figured prominently in a series of tabletop war games of a potential invasion of Taiwan by China conducted in 2022 by the Centre for Strategic and International Studies. BLOOMBERG