Maritime clashes between the Philippines and China had been mostly over the Philippines’ military outpost, BRP (BRP – Barko ng Republika ng Pilipinas, which translates to “Ship of the Republic of the Philippines” – the ship prefix for the Philippines) Sierra Madre, in the Spratly Islands, which is disputed by Brunei, China, Malaysia, the Philippines, Taiwan (a province of China, as recognized by the United Nations’ Resolution No. 2758), and Vietnam. The BRP Sierra Madre was intentionally run aground on a reef near the Second Thomas Shoal in the disputed Spratly Islands, in 1997, so that the Philippines could stake their territorial claim.
The WWII-era ship is rusted out and on its way to disintegrating. In December 2023, the Philippines allocated funds to replace the ship with a permanent structure. Coincidentally, in September 2023, Blake Herzinger, a research fellow at the United States Studies Centre of the University of Sydney, penned an article titled, “It’s Time to Build Combined Forward Operating Base Sierra Madre.” This outpost would be “manned by combined rotational forces from both the Philippines and the U.S. Marine Corps,” according to Herzinger. In it, he admits that doing so, “would be a provocative move, and it would not be without significant risk.”
In October 2023, the Armed Forces of the Philippines (AFU) admitted that their resupply missions to the BRP Sierra Madre were carrying materials that were used in the maintenance and repair of the ship. China had been accusing the Philippines of using its resupply missions to send “illegal building materials” to reinforce the dilapidated ship on several occasions. In June of this year, The Financial Times revealed that the Philippines had “secretly” reinforced the BRP Sierra Madre at the Second Thomas Shoal.
On March 5, 2024, in response to an incident at the Second Thomas Shoal, U.S. State Department Spokesperson Matthew Miller stated that “Article IV of the 1951 U.S.-Philippines Mutual Defense Treaty extends to armed attacks on Philippine armed forces, public vessels, or aircraft, including those of its coast guard, anywhere in the South China Sea.” At the time, the crash was “not the time or reason to invoke a Mutual Defense Treaty with the United States,” according to Philippine President Bongbong Marcos. Invoking the Mutual Defense Treaty by the Philippines could lead to an armed conflict between China and the U.S. Military.
Recently, these clashes have been occurring at the Sabina Shoal, another disputed atoll in the Spratly Islands. In May, the Philippines claimed that China was carrying out “small-scale reclamation” and anchored the BRP Teresa Magbanua at Sabina Shoal to “catch and document the dumping of crushed corals over the sandbars” (China denied this). The Philippines had been using the BRP Teresa Magbanua as a staging area for their resupply missions to the BRP Sierra Madre at Second Thomas Shoal. A new Philippine Coast Guard vessel was sent to Sabina Shoal, according to Jonathan Malaya, the spokesperson for the National Security Council of the Philippines, on September 26. However, he declined to comment on the specifics of their intentions or plans, citing operational security concerns.