Features

By Jennifer Jun, Asia Maritime Transparency Initiative, and Victor Cha Sources: CSIS Beyond Parallel; Republic of Korea Navy Headquarters Report submitted to the South Korean National Assembly, shared with the press Key Findings This report focuses on China’s marine observation buoys in and adjacent to the Provisional Measures Zone (PMZ) in the waters between China […]

China’s artificial island bases have been out of the spotlight in recent years, with most coverage of the South China Sea instead focused on the activities of China’s coastguard, navy, and militia—or on Vietnam’s eye-catching efforts to expand its own outposts. But in the years since AMTI last looked at Chinese island upgrades in 2022, […]

The Philippine Coast Guard on October 15 released photos of two newly installed Chinese buoys at Scarborough Shoal. Coming in the wake of security concerns from South Korea over similar Chinese floating structures in the Yellow Sea, the buoys’ installation has raised alarms in Manila over the possibility that Beijing’s increasing efforts to assert control […]

By Jennifer Jun, Asia Maritime Transparency Initiative, and Victor Cha Left: Image of the Shen Lan 1, the first of the two aquaculture cages to be deployed inside the South Korea-China Provisional Measures Zone (PMZ), tethered to a support vessel. Right: View of the Shen Lan 2, May 30, 2025. Copyright © 2025 Vantor. Image […]

On September 10, China announced the establishment of a nature reserve at Scarborough Shoal. The area in question, however, conspicuously overlaps with an area that has sustained major damage from Chinese clam harvesting. The Nature Reserve The reserve covers an area of about 8,700 acres along the northeastern side of Scarborough. It consists of two […]

Since the start of 2025, Vietnam has expanded its island-building efforts to eight features previously untouched by the current round of reclamation that Hanoi began in 2021. New Dredging Recent satellite imagery shows that Vietnam has undertaken dredging and landfill work at Alison Reef, Collins Reef, East Reef, Landsdowne Reef, and Petley Reef, all of […]

China constructed two new oil and gas platforms in the East China Sea in May and June, drawing formal protests from Japan. But in addition to these new permanent structures, satellite imagery and automatic identification system (AIS) data shows that at least three mobile drilling rigs have also been active in the area, supporting both […]

In late February 2025, South Korean research vessel Onnuri made its way to the Provisional Measures Zone (PMZ) shared between South Korea and China. The vessel was deployed to survey one of three Chinese steel structures that were installed in the PMZ without prior notice to South Korea. The vessel’s journey was unsuccessful, as the Chinese coast […]

In the wake of an agreement last July to reduce tensions at Second Thomas Shoal, Scarborough Shoal has reemerged as the focal point of tensions between Manila and Beijing in the South China Sea. China has maintained a permanent coast guard presence at Scarborough since it seized control of the feature from the Philippines in […]

As part of efforts to achieve independence from Chinese supplies of critical minerals, the Trump administration has expressed renewed U.S. interest in deep sea mining. An April 24 executive order titled Unleashing America’s Offshore Critical Minerals and Resources aims to rapidly develop U.S. seabed mining capabilities, including expediting the process for issuing mining licenses in […]

After the official opening of Cambodian-Chinese joint facilities at Ream Naval Base in early April, the base quickly hosted visits from both Japan and Vietnam. But closer examination of those visits, as well as the physical layout of infrastructure at Ream, suggests that China maintains exclusive access to some facilities, including the base’s largest pier. […]

Vietnam has considerably expanded its Spratly Island outposts over the last ten months, completing a record year of island building in 2024 and moving on to dredge in new areas even as some features approach completion. Since AMTI’s last update in June 2024, Vietnam has created 641 new acres of land, continuing at the breakneck […]

Satellite imagery analysis shows that China’s maritime militia deployed to the South China Sea in record numbers in 2024.  But in contrast to recent years, a majority of ships spent most of their days anchored at China’s military outposts rather than at unoccupied reefs where they might pretend to fish. This suggests Chinese authorities are […]

Despite a turbulent 2024 in the South China Sea, at least one constant remained: the China Coast Guard’s (CCG) presence was ubiquitous but seemingly unable to impose Beijing’s will on other claimants. Analysis of AIS data from commercial provider Starboard Maritime Analytics shows that Beijing maintained daily patrols at key locations across the South China […]

Global public awareness of China’s maritime militia has grown dramatically over the past several years. Once a shadowy group who, outside of China, was known only to experts in Chinese maritime and fisheries policy, videos of militia vessels actively supporting the China Coast Guard (CCG) in confrontations with the Philippines have now become a familiar […]

This February, Beijing vowed to increase China Coast Guard (CCG) patrols around the Taiwan-administered Kinmen islands following an incident between Taiwan’s Coast Guard Administration (CGA) and a Chinese motorboat. The CGA has since reported numerous cases in which CCG vessels entered the restricted and prohibited waters around Kinmen and Matsu. But both Taiwan and the […]

Vietnam now has two airstrips in the Spratly Islands—but it may not be long until it gets another. As reported October 25 by Radio Free Asia, Vietnam has begun laying down a runway on Barque Canada Reef. The area currently being prepared for paving is approximately 8,000 feet long—twice the length of Vietnam’s existing runway […]

The China Coast Guard (CCG) is in its 12th day facing off against Indonesian law enforcement and naval vessels over oil and gas resources in the northern portion of the latter’s continental shelf in the South China Sea. While the Indonesian Maritime Security Agency (Bakamla) has reported multiple times that it succeeded in expelling the […]

The U.S.-Philippine alliance is experiencing a renaissance. Driven by unrelenting pressure from Beijing on Philippine activities in the South China Sea, Manila has pushed forward with Washington on a range of measures to modernize the alliance and give substance to the commitments outlined in the 1951 Mutual Defense Treaty. Even as Washington and Manila work […]

The leak of a diplomatic letter last month in which China urged Malaysia to halt its offshore oil and gas activities near Luconia Shoals has brought renewed attention to undersea resources in the South China Sea. In the wake of the letter’s publication, Malaysian prime minister Anwar Ibrahim gave a rare public acknowledgement of Beijing […]

Though tensions have been growing between China and the Philippines at Second Thomas Shoal since 2021, shifts in tactics by Chinese coast guard and militia in 2024 have led to more damage being sustained by Philippine vessels, more injuries to Philippine personnel, and a higher risk of escalation. On June 17, a Philippine resupply mission […]

Intrusions by Chinese military aircraft into Taiwan’s air defense identification zone (ADIZ) have increased dramatically in the last four years, contributing to global fears about a potential conflict in the Taiwan Strait. Amidst this historic upturn, Japan in April reported the lowest annual number of air scrambles responding to foreign military activity within its ADIZ […]

Vietnam has significantly accelerated the expansion of its outposts in the Spratly Islands over the last six months, creating almost as much new land as it had in the previous two years combined and putting Hanoi on pace for a record year of island building in 2024. Since AMTI’s last update in November of 2023, […]

Two Chinese navy ships have now spent over four months at Cambodia’s Ream Naval Base, the first and only two ships to have docked at a new pier built at the base with Chinese funding. This extended and exclusive access to the new pier comes after years of concerns expressed by the United States and […]

The China Coast Guard (CCG) remains the dominant state actor in disputed waters of the South China Sea. Analysis of AIS data from commercial providers MarineTraffic and Starboard Maritime Analytics show that the CCG continued to maintain daily patrols at key features across the South China Sea in 2023.  Taken together with the CCG’s leadership […]

China’s maritime militia, once a shadowy and ill-understood actor in the South China Sea disputes, has become visible to international observers in a very tangible way over the last year. Increasing numbers of militia vessels have been involved in collisions and tensions with the Philippines at Second Thomas Shoal, and their close coordination with the […]

Over the last two years, tensions between China and the Philippines at Second Thomas Shoal have emerged as the focal point of frictions in the South China Sea. The Philippines maintains a detachment of marines at Second Thomas Shoal stationed aboard the BRP Sierra Madre, a Philippine navy ship intentionally grounded there in 1999. Ever […]

A hidden crisis is unfolding across the South China Sea. While regional powers work to strengthen their claims to disputed waters and territories there, the marine environment in which they maneuver has been declining to critical levels. In recent decades, increased fishing, dredging, and land fill, along with giant clam harvesting, have taken a devastating […]

Southeast Asia is a distinctly maritime region. Nine out of ten Southeast Asian states are coastal states, with two of them (Indonesia and the Philippines) being the world’s largest archipelagic states. Southeast Asian waters host major sea lines of communication between the Indian and Pacific oceans, and most Southeast Asian states are either major flag […]

Over the last year, Vietnam has continued with a substantial program of dredging and landfill work in the Spratly Islands which began in 2021. Since AMTI last surveyed these efforts in December 2022, Vietnam has created another 330 acres of land, bringing its total during the current spate of building to 750 acres. By contrast, […]