The Armed Forces of the Philippines (AFP) is accelerating plans to acquire submarines as it faces mounting pressure from China’s incursions into the West Philippine Sea, part of Manila’s exclusive economic zone in the South China Sea.
“We are an archipelagic nation, so we have to have this capability because it is extremely difficult to defend our vast maritime territory without submarines,” Gen. Romeo Brawner Jr., the AFP’s chief of staff, said in February 2025.
Manila included a submarine capability in its Horizon 3 defense modernization plan in 2022, although procurement initially was not a priority.
Since then, however, Chinese vessels have frequently swarmed Philippine outposts and obstructed resupply missions, including by employing aggressive tactics such as ramming and firing high-powered water cannons. Submarines would serve as a deterrent, complicating Beijing’s destabilizing maritime operations.
A submarine program, combined with Philippine Marine Corps anti-ship missile batteries, would “provide the Philippine Navy with an asymmetric capability to deal with the [Chinese] People’s Liberation Army Navy surface fleet,” according to retired Rear Adm. Rommel Jude Ong, a former Philippine Navy vice commander.
“Together, they support the Philippine Navy’s sea denial strategy in the West Philippine Sea,” he told FORUM. “A submarine capability allows the Philippines to work on a cost imposition strategy, targeting Chinese vulnerability: its international trade, which is dependent on the sea.”
The Philippine Navy has established a study group to prepare for submarine acquisitions, initially focusing on strategic planning and doctrine development.
The submarine program also must encompass infrastructure for basing and maintenance, technology transfers, and training, Ong noted.
The Philippine Navy recently joined the International Submarine Escape and Rescue Liaison Office, paving the way for a delegation from its Submarine Group to participate in Invitex Kurtaran 2025, a multinational submarine search and rescue drill held in late April near Turkey’s Aksaz Naval Base in the Eastern Mediterranean.
In March 2025, Philippine Navy chief Vice Adm. Jose Ma Ambrosio Ezpeleta and United States Navy Rear Adm. Christopher Cavanaugh discussed strengthening cooperation, including potential U.S. support in boosting the Philippine Navy’s anti-submarine warfare capabilities.
The commanders also addressed joint exercises, development of uncrewed underwater systems and training Philippine Navy personnel in operating uncrewed surface vessels.
