United States (US) State Secretary Antony J. Blinken’s visit to the Philippines will help Manila maintain a rules-based order in the South China Sea.

Commodore Roy Vincent Trinidad, PN spokesperson for West Philippine Sea, made the remark on Wednesday, March 20, as he noted that the Philippines is “at the frontline of the expansionist ambitions of China.”

“We have to understand that China's nine-dash line claims 75 to 80 percent of the South China Sea. The issues are not… the conflict is not only with our exclusive economic zone (EEZ) but also other countries in the Southeast Asia area,” the navy official explained.

China claims almost the entirety of South China Sea using its so-called 10-dash line, a segment that features the areas it deems as its own, which is based on the former nine-dash line that had been rejected by the Permanent Court of Arbitration (PCA) in 2016.

Because of this, Trinidad said Manila has a security concern on its territory all the way up to its EEZ. 

He said this was the very reason why the Department of National Defense (DND) adapted a new defense concept called the Comprehensive Archipelagic Defense Concept (CADC) which aims to protect the country’s entire territory up to its EEZ.

“We don’t care what China will do so long as what is ours will remain ours: we will have access to our detachments, we will have access to northern islands, we would have the capability to protect and to secure Benham Rise (now Philippine Rise), all the way... all around the country,” Trinidad said.

On the international level, Manila has a responsibility to keep the sea lanes of communication open and maintain the rules-based order, according to Trinidad.

“The international community would like to show that they are one in supporting us when it comes to changing the rules based international order,” he said. “No one country can change the rules based international order unilaterally.”

Blinken met President Marcos Jr. on Tuesday, March 19, and underscored Washington’s iron-clad support for Manila in the South China Sea, where China has maintained a strong presence through the deployment of its vessels.

On the same day, at least 30 Chinese vessels have been monitored in the West Philippine Sea (WPS) by the Armed Forces of the Philippines (AFP).

As of 4:30 p.m. Tuesday, there were six China Coast Guard (CCG) and eight maritime militia vessels in Bajo de Masinloc (Scarborough Shoal), said AFP spokesperson Col. Francel Margareth Padilla.

The number of CCG vessels in Bajo de Masinloc was relatively higher than their usual deployment of two ships.

Meanwhile, there was one CCG ship and six fishing vessels in Ayungin (Second Thomas) Shoal; one CCG ship, one People’s Liberation Army (PLA) Navy vessel, and six fishing vessels in Pagasa Thitu) Island; and one fishing vessel in Lawak (Nanshan) Island. 

Trinidad said the Navy was not alarmed by the increased deployment of CCG vessels in Bajo de Masinloc.

“It’s not alarming. Their presence has been fairly constant. If we graph it over a good number of years, there was no major spike. It will become alarming if it will be beyond the capability of [China’s] South Sea Fleet,” he stated.

“We have to understand that the South Sea fleet is what China has in the South China Sea but they are not only what we engage. The South Sea Fleet also faces Vietnam, Indonesia and the other countries that they have overlapping claims,” the navy official added.

On April 11, Marcos will attend a meeting with US President Joe Biden and Japanese Prime Minister Fumio Kishida in US to strategize how the three nations can keep a “free and open” Indo-Pacific region amid China's presence.