Earlier this month, China announced the establishment of new baselines surrounding Scarborough Reef, a significant coral atoll in the South China Sea that has been a focal point of territorial disputes. This declaration was viewed as a strategic reaction to the Philippines' recent implementation of maritime legislation intended to protect its claims to the reef, contributing to the ongoing legal and maritime contention between the two countries in a region crucial for global trade.

The Philippines swiftly condemned China's claim, asserting it infringes upon established Philippine sovereignty over Scarborough Reef. The Philippine Defense Secretary expressed concern that the escalating tensions could lead to confrontations at sea, underscoring the seriousness of the situation.

Scarborough Reef, known as Huangyan Dao by China and Bajo de Masinloc by the Philippines, is located to the northwest of the Philippine island of Luzon. It is primarily a small group of islets that almost vanish at high tide and is the largest coral atoll in the area during low tide. China's extensive claim over the South China Sea includes Scarborough Reef, and this has led to numerous altercations with the Philippine fishing vessels that wish to access the lagoon.

Since 2012, the reef has become a site of confrontation, with China preventing Filipino fishermen from traditional fishing activities, prompting the Philippines to seek international arbitration under UNCLOS. The 2016 arbitration ruling favored the Philippines, declaring that China lacked historical rights that would conflict with internationally agreed regulations, which China has consistently rejected.

In its recent actions, China specified geographic coordinates defining its territorial claim around Scarborough Reef. The establishment of baselines is standard practice for nations wishing to claim maritime territory and is crucial for determining territorial seas, which can extend up to 12 nautical miles from these baselines. Countries often aim to extend their maritime boundaries as much as possible, seeking increased control over resources and law enforcement within those areas.

China's baselines around Scarborough Reef are somewhat conservative, extending only slightly further out to sea than before, and signaling a shift from its broader claims to the Zhongsha Islands. The establishment of these new baselines may indicate a more assertive approach by China, particularly with increased patrols by the China Coast Guard, which has pledged to enforce laws in the area.

As tensions mount over fishing rights and territorial claims, observers anticipate that China's ongoing assertiveness may extend to other contested regions, including the Spratly Islands. This archipelago, claimed by multiple countries, could face similar protests from neighboring nations if China attempts to claim it through additional baselines, raising concerns of further maritime disputes in the South China Sea.