The South China Sea in 2025 - A Year in Review Part 1: Multiple flashpoints in Philippines-China interactions; Closer Intra-ASEAN Military connectivity

 

 

By the end of 2025, at least 15 incidents of incidents and close encounters had occurred between the Philippines and China across multiple locations, including Second Thomas Shoal (Bãi Cỏ Mây), Scarborough Shoal (Bãi cạn Scarborough), Sabina Shoal (Đá Sabin), Sandy Cay (Đá Hoài Ân), and adjacent waters. From a broader view, maritime incidents between the Philippines and China unfolded continuously throughout the year, occurring on a near-monthly basis and collectively constituting multiple flashpoints in the South China Sea (see map).

 

In these incidents, China’s practices to exert pressure included harassment of scientific survey activities, the use of water cannons, and the deployment of armed small craft to closely approach vessels of the Philippine Bureau of Fisheries and Aquatic Resources (BFAR), as well as resupply ships. Incidents were most heavily concentrated around Scarborough Shoal (from February to June, and again in August and November), thus underscoring its role as a core flashpoint in China-Philippines tensions in 2025.

 

During the first half of the year, the two sides experienced 10 incidents, six of which occurred at Scarborough Shoal alone. In February, helicopters of the Chinese Navy repeatedly flew within three meters of BFAR patrol aircraft, prompting emergency warnings from the Philippine side. In April, a Chinese maritime surveillance vessel cut across a Philippine vessel at a distance of 36 nautical miles, while Chinese naval ships (BN-554 and BN-573) maneuvered close to the Philippine Navy’s BRP Emilio Jacinto. On 22 May, a Chinese maritime surveillance vessel used water cannons and maneuvered dangerously close to a Philippine scientific research ship near the Sandy Cay

 

In the second half of 2025, China and the Philippines recorded five additional incidents, ranging from radio warnings and water cannon use to the forcible expulsion of fishing vessels, nearly double the total number of three incidents recorded during the same period in 2024. Notably, on 11 August 2025, while pursuing the Philippine patrol vessel BRP Suluan, which was escorting fishing boats near Scarborough Shoal, China Coast Guard vessel No. 3104 collided with a PLA Navy Type-052D destroyer operating in the same area, causing severe damage to the coast guard vessel.

 

A second cluster of incidents emerged around Second Thomas Shoal and Sandy Cay, with notable incidents occurring in January, May, August, and October. Tensions escalated as early as January 2025 in the area surrounding Sandy Cay, and reached he peak during a ship collision on 12 October 2025. While three Philippine government vessels were anchored near Thitu Island to assist local fishermen, a Chinese coast guard vessel approached, deployed water cannons, and subsequently rammed the stern of BRP Datu Pagbuaya, causing material damage.

2. Closer Intra-ASEAN Military Connectivity

 

Throughout 2025, Southeast Asian countries participated in at least 57 joint maritime exercises and patrols, exceeding the 2024 total by nine activities. The year marked a notable expansion in intra-ASEAN military training and exercise linkages.

 

During the first six months of 2025, Southeast Asian states took part in 43 joint exercises and patrols, a sharp increase from 22 activities during the same period in 2024, and nearly equivalent to the entire 2024 total of 48 exercises. Particularly in April 2025, the number of joint maritime activities increased by approximately 2.5 times compared to April 2024. As in previous years, bilateral and multilateral exercises involving the United States and the Philippines accounted for a significant share of these activities.

 

In the second half of 2025, ASEAN countries participated in 14 exercises, including both intra-regional activities and engagements with external partners, 11 fewer than the 25 exercises recorded during the same period in 2024.

 

While 2024 exercises largely revolved around a few frequently cooperating pairs/groupings, most notably Indonesia-Singapore, Malaysia-Singapore, Singapore-Thailand, and a single trilateral activity involving Cambodia-Laos-Vietnam, 2025 saw broader intra-ASEAN connectivity, highlighted by the revival of the ASEAN Multilateral Naval Exercise (AMNEX). Bilateral naval cooperation between Vietnam and the Philippines, as well as Vietnam and Thailand, was also significantly strengthened during this period.

 

Although the situation in the South China Sea overall remained under control in 2025, conflict flashpoints and the intensity of confrontations showed no signs of abating, alongside a growing trend toward expanded military exercises and capacity-building activities. Accordingly, in 2026, Vietnam and other regional states will need to closely monitor developments, identify patterns and drivers of incidents and confrontations, and promote measures to enhance regional security in pursuit of a peaceful and prosperous South China Sea.