In a policy departure with ramifications for regional peace and stability, US President Donald Trump’s administration has explicitly reaffirmed its obligations to the Philippines under their 1951 Mutual Defense Treaty (MDT).

US Secretary of State Mike Pompeo said on March 1 during a visit to Manila that his country would defend the Philippines if it came under attack from China in relation to a years-long island dispute in the South China Sea.

Pompeo said after meeting with Foreign Secretary Teodoro Loscin that any armed Chinese attack on Philippine forces, aircraft or public vessels in the South China Sea would trigger mutual defense obligations under the treaty’s Article 4.

It marked the first time the US had explicitly said it would defend the Philippines’ position in the contested South China Sea.

Pompeo’s shift is a reflection of Washington’s increasingly adversarial relations with Beijing, as well as US concerns over Manila’s recent call for a “review” of the MDT, a process some believe could lead to the treaty’s eventual abrogation.

President Rodrigo Duterte’s top officials are now at open odds over the country’s alliance with the US. Locsin has indicated that Washington’s recent pronouncements provide sufficient guarantees despite vagueness in the treaty’s language.

Philippine Defense Secretary Delfin Lorenzana at the military headquarters of Camp Aquinaldo in Quezon City, metro Manila, on February 9, 2017. Photo: Reuters/Romeo Ranoco

Defense Secretary Delfin Lorenzana, on the other hand, is championing the cause of reviewing the treaty, arguing that it may have outlived its usefulness without more explicit language and guarantees from the US.

He has also expressed concern that the Philippines could get dragged into a US-China conflict in the South China Sea even if its interests were not directly at stake.

“The Philippines is not in a conflict with anyone and will not be at war with anyone in the future,” Lorenzana said on Tuesday. “But the United States, with the increased and frequent passage of its naval vessels in the [South China Sea], is more likely to be involved in a shooting war. In such a case and on the basis of the MDT, the Philippines will be automatically involved.”

The upshot is a seeming split within the Philippine government on whether to downgrade or enhance security relations with the US, crucially at a time when tensions are mounting between Washington and Beijing over control of the South China Sea.

While in Manila, Pompeo also highlighted Washington’s growing concern over “China’s island building and military activities in the South China Sea” and how it “threaten[s] sovereignty, security and therefore economic livelihood” of allies such as the Philippines “as well as that of the United States.”

The Jimmy Carter and Bill Clinton administrations maintained a similar position to Trump’s harder line, though neither US administration made such a high-profile and overt statement on the issue.

Moreover, Pompeo underscored the fact that “the South China Sea is part of the Pacific,” thus the direct geographical applicability of the MDT, which doesn’t mention the South China Sea in name but rather the Pacific in more generic terms.

The Trump administration has progressively clarified the extent of its commitment to assist the Philippines amid the ongoing disputes in the South China Sea.

Over the past year, senior Pentagon officials have made it clear that the US will be a “good ally” and “defend” the Philippines against any external attack. Pompeo’s statement thus marks the culmination of earlier efforts at reassuring Manila of the utility of the alliance.

What made Pompeo’s statement even more crucial, however, is the fact that the Obama administration was notoriously ambivalent over the precise coordinates of its treaty commitments to the Philippines.

US Secretary of State Mike Pompeo speaks during a news conference in Manila on March 1, 2019. Photo:AFP/Andrew Harnik/Pool

On multiple occasions, then-president Barack Obama and his senior officials dismissively described the disputes as unnecessary squabbling over a “bunch of rocks.”

Amid a months-long naval standoff between China and the Philippines in mid-2012, Washington largely stood by even when Beijing coercively wrested control of the Philippine-claimed Scarborough Shoal in mid-2012.

Security analysts believe the shoal would be a crucial outpost for China should it ever move to declare an Aerial Defense Identification Zone (ADIZ) over the South China Sea.

Under Trump, Washington has conducted more regular and aggressive “freedom of navigation operations” (FONOPs) that challenge China’s claims and reclamation activities in the area. At the same time, his government has doubled its Foreign Military Financing (FMF) to allies such as the Philippines.

In response to his American counterpart’s comments, Locsin has openly questioned Loreznana’s position on reviewing the MDT. The Filipino chief diplomat even openly criticized the move, saying it “requires further thought,” since “we are very assured, we’re very confident, that the United States has – in the words of Trump to our president – we have your back.”

A protester holds a placard during a demonstration in Manila against China’s presence in disputed waters in the South China Sea. Photo: AFP/Ted Aljibe

On Tuesday, the Philippine defense chief rejected Locsin’s statement, arguing that the “vagueness” of the MDT would undermine its ability to act as a “deterrent” against external aggression against the Philippines.

“I do not believe that ambiguity or vagueness of the Philippine-US Mutual Defense Treaty will serve as a deterrent. In fact, it will cause confusion and chaos during a crisis,” Lorenzana said, insisting on the necessity for a formal review and if necessary to amend or abrogate it.

“The fact that the security environment now is so vastly different and much more complex than the bipolar security construct of the era when the MDT was written necessitates a review of the treaty,” he added.

Though not opposed to long-standing security cooperation between the Philippines and the US, Lorenzana and other top security officials believe that the MDT is increasingly obsolete and needs key amendments in order to stay relevant to new and emerging security challenges.

If so, it wouldn’t be the first time the two allies formally reviewed their alliance. In 2001, at the onset of the “global war on terror,” the US and the Philippines revised operational interpretations of the MDT, which was crafted at the beginning of the Cold War, in order to deal with emerging 21st-century threats from transnational terror groups and other non-state actors.

US and Philippine troops at a joint exercise event in a file photo. Photo: Reuters

Defense experts and government officials believe that the MDT should once again be reviewed and upgraded in light of China’s naval expansion and territorial assertiveness in the South China Sea.

In particular, there are growing concerns in Manila over China’s so-called “gray zone” tactics, namely the deployment of paramilitary and militia forces to surround, intimidate and coercively displace other claimant states in the sea’s disputed areas.

China’s gray-zone strategy has been on full display in recent months, with Chinese paramilitary forces swarming Philippine-held Thitu Island and other features, intimidating Filipino fishermen and squeezing supply lines of Philippine troops.

The problem, however, is that the MDT provides no specific guidelines on hybrid threats to Philippine sovereignty.

Duterte, who has favored closer ties with China at the expense of the US, has yet to comment on his officials’ treaty review dispute. What’s clear, however, is that there is a growing call in the Philippines to tweak or even overhaul its US alliance while looking askance at China.