The Spratly Islands' Second Thomas Shoal, known as Ayungin Shoal in the Philippines and Ren’ai Reef in China, is uninhabited save for the rusting World War II–era warship BRP Sierra Madre, grounded on the feature in 1999 to stake the country’s claim.
China claims most of the South China Sea as its territory, including Scarborough Shoal, and between 2023 and mid-2024, Chinese maritime forces repeatedly intercepted Philippine supply missions, leading to sometimes dramatic clashes that left several Philippine injuries and raised concerns that a miscalculation could trigger the Philippines’ Mutual Defense Treaty with the United States.
