MANILA — Changes in the geopolitics and China's continuing aggression in the South China Sea led the Philippines to intensify its relations with the United States, analysts have said.

Manila and Washington this week issued the bilateral defense guidelines, which laid out plans to modernize alliance cooperation for the two countries' "shared vision for a free and open Indo-Pacific region."

The guidelines, which experts considered as an expanded interpretation of the 1951 Mutual Defense Treaty (MDT), aimed to intensify joint patrols, modernize the country's armed forces, and prioritizes the US' military assistance to the country.

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Aside from this, it emphasized and reaffirmed that any armed attack on the two countries' Coast Guards in the South China Sea would trigger the MDT.

International studies expert Renato De Castro lauded the bilateral defense guidelines, noting that it "updated and modernized" the defense treaty.

"There’s no need to change the text, the provisions of the 1951 Mutual Defense Treaty. What is very significant here is we have come out with the mutually acceptable interpretation and operationalization of this 1951 MDT," De Castro told ABS-CBN News in an interview.

The document also gives a warning to China that they "won’t be facing the Philippine Coast Guard alone" in the disputed waters.

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"I don’t think it would lead to lesser tension but... the Chinese would have to take into account that it will now encounter joint maritime operations," he said.

The signing of this new document was a "major achievement," said Dennis Coronacion, University of Santo Tomas' Political Science department chair.

Coronacion said this came after China showed "an aggressive stance in terms of enforcing its claim over the South China Sea territory."

As of Wednesday, hundreds of Chinese maritime militia vessels remained in most parts of the Julian Felipe Reef, just as it ignored Filipino authorities who told them to leave.

A week before, a Philippine Coast Guard (PCG) vessel carrying journalists nearly collided with a Chinese vessel.

"Kahit anong aggressive behavior against Philippine Coast Guard would be considered as a basis for the US to come to our defense, even yung public vessels," Coronacion told ABS-CBN News.

"Definitely may mga previous events that could fall under what is being contemplated by the guideline like the military-grade laser-pointing made by the Chinese Coast Guard or the Navy," he added.

In a media forum on Saturday, Chester Cabalza, founding president of the International Development and Security Cooperation, said Marcos' US visit could have an effect on the country's relations with China.

It was also possible that China could reach out to the President after his string of visits to the US, United Kingdom, and Indonesia for the upcoming ASEAN Summit.

"Sigurado ang China may pinaplano yan sa atin dahil alam natin na malakas yung competition ng US and China," Cabalza told reporters in a chance interview.

He also described Marcos visit to Washington as a "threat" to China.

Marcos Jr.'s trip to Washington DC came as the Philippines and the US seek to counter Beijing's growing assertiveness over self-governed Taiwan and China's construction of bases in the South China Sea.

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In early April, the Philippines announced 4 new sites for the US military to use under the Enhanced Defense Cooperation Agreement (EDCA), drawing the ire of Beijing.

"Definitely, kaya nagpunta ang foreign minister nila (China) dito, para tanungin kung anoing nangyayari sa ugnayan ng Pilipinas at Estados Unidos lalong-lalo na sa ngayon, pinaplantsa natin ang lenggwahe ng EDCA sites na ito," Cabalza said.

PH-US RELATIONS

But what led the Philippines to pivot to the United States? De Castro said it was China's tactics.

The analyst noted that the previous administration's "appeasement" of China did not lead to lesser incidents in the disputed waters.

"It is China that pushed us to closer security relations with the United States because of its coercive and uncompromising stance in the West Philippine Sea, South China Sea dispute," de Castro said.

"China has nothing to blame but itself for pushing us for a closer alliance with the United States. We gave China 6 years. The previous Duterte administration applied an appeasement policy that crackly put our head in the silver platter and offered it to China. What did we get in return?"

Coronacion, for his part, said the President's visit was timely as it sought warmer ties with the superpower.

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It could, however, stoke tensions in the West Philippine Sea or send "strong message to China that it should stop its aggressive behavior and hostile actions in the South China Sea."

'KEEP OUR EYES OPEN'

When asked if the bilateral defense guidelines could escalate tensions in the disputed waters, former National Security Adviser (NSA) Clarita Carlos said, "we’ll see where that goes."

"More and more we are getting tucked into the defense alliances of the United States and we have to ask ourselves, is this in our national interest? Or are we being dragged unnecessarily because of the tension beyween the China and the US," said Carlos in a phone interview.

"I think we should keep our eyes open… because our core national interest is not the same national interest of the US," she added.

Carlos said the defense guidelines were still relevant amid the changing geopolitical situation "for as long as it is not directed at any country."

"China is not our enemy," said the former NSA.

"We will be at a disadvantage here if we are so being naive to be disadvantaged. You cannot disadvantage yourself. You should be smart, intelligent about it and make sure that the United States and the Philippines are in fact working on the same level-field."

She hoped that multipolarity and multi-alignment were still the basic principles of Marcos' foreign policy.

In a separate forum, Ado Paglinawan, vice president for internal affairs at the Asian Century Philippines Strategic Studies Institute, slammed Marcos' closer ties with the US.

Paglinawan believed the EDCA sites can be used for war.

"There is no more recourse here except... EDCA cannot be facelifted anymore because the motivations are obvious. The US will use it to put up China in the next war. Does it have to be defined?" Paglinawan said in a media forum.

"We are going backwards. What's the recourse here? Abolish EDCA. Abrogate DFA. Abrogate the Mutual Defense Treaty."

The analysts though hoped Marcos' visit would help the country in the long-term.

For De Castro, the weeklong visit affirms the fact that the Philippines "learned from its mistake" with China.

Our mistake was thinking that by appeasing China, we can solve the West Philippine Sea issue. No, it became more complicated because China thought it has won over us, it can simply push us around," he said.

Coronacion, meanwhile, hoped the country would not be at the losing end of any deals made during the visit.

"I hope mayroon tayong ma-gain unlike in the past na parang lugi tayo. Kasi any alliance is founded on mutual benefit of the parties involved."