What is the risk of conflict at the disputed Scarborough Shoal?

MANILA - The Philippines on Tuesday vowed not to back down against a Chinese move to block its fishermen from a hotly contested area of the South China Sea.

Beijing has warned against provocations after Manila

severed its floating barrier.

What is happening at the Scarborough Shoal?

The Philippines expressed outrage at the weekend after its coastguard discovered a 300m-long ball-buoy barrier policed by China's coastguard near the disputed, China-held Scarborough Shoal, during what it said was a routine patrol.

On Monday, the Philippines executed a "special operation" that entailed the coastguard entering the shoal on a small motor boat posing as fishermen, before diving down with snorkels and masks to cut the barrier and remove its anchor.

The Philippines coastguard said the mission was approved by President Ferdinand Marcos Jr.

The coastguard said its action showed its determination to maintain a presence at the shoal.

China's foreign ministry advised the Philippines against provocations.

What is the significance of the shoal?

Named after a British ship that was grounded on the atoll nearly three centuries ago, the Scarborough Shoal is one of Asia's most contested maritime features and a flashpoint for diplomatic flare-ups over sovereignty and fishing rights.

The shoal is located 200km off the Philippines and inside its exclusive economic zone.

It is coveted for its bountiful fish stocks and a stunning turquoise lagoon that provides safe haven for vessels during storms.

Located in the middle of the South China Sea and near shipping lanes carrying an estimated US$3.4 trillion (S$4.7 trillion) of annual commerce, its position is strategic for Beijing.

There are concerns China might one day build a man-made island there, as it has on submerged reefs in the Spratly islands, some equipped with radar, runways and missile systems.

A Chinese official responsible for those islands in 2017 said Scarborough Shoal would be among several sites where environmental monitoring stations would be built, though its foreign ministry later dismissed that.

Who does the shoal belong to?

The Philippines and China lay claim to the shoal but sovereignty has never been established and it remains effectively under Beijing's control.

A landmark 2016 ruling on the South China Sea by the Permanent Court of Arbitration, which went largely in favour of the Philippines, was not tasked with establishing sovereignty.

It ruled China's blockade of the shoal violated international law and said the area was a traditional fishing ground for several countries.

China seized the shoal in 2012 after a standoff with the Philippines and has since maintained a constant deployment of coastguard and fishing trawlers, some accused by Manila of being maritime militia.

China has not acknowledged the presence of militia in the South China Sea.

Up until now and during the 2016-2022 administration of pro-China former Philippine President Rodrigo Duterte, China's coastguard allowed Filipino fishing boats to operate near the shoal, mostly small vessels on a scale dwarfed by China.

What is the risk of conflict?

The stakes are high for both countries and the region should tensions increase.

There have been minor altercations elsewhere in the South China Sea this year, including at the Second Thomas Shoal.

Manila has accused Beijing of dangerous and aggressive conduct there, including the

use of a military-grade laser.

Standing up to Beijing might score points for President Marcos among Filipinos, but his coastguard is under-equipped and no match for China's.

Any deployment of navy vessels would be a red line both sides would most likely steer clear of.

One deterrent could be the United States and a recent strengthening of defence ties between Manila and Washington would up the stakes should China respond militarily.

After years of lobbying, Mr Marcos in May received guidelines from the US on when it would come to the rescue of the Philippine under a 1951 Mutual Defence Treaty.

The Pentagon stated mutual defence commitments would be invoked over an attack "anywhere in the South China Sea" and that coastguard vessels are among those protected. REUTERS