The Maritime Boundary Challenge in Vietnam-Philippines Relations

While there were a range of issues discussed when Philippine President Rodrigo Duterte met with Vietnamese Prime Minister Nguyen Xuan Phuc in Bali on October 11 on the sidelines of an ASEAN leaders’ meeting, the headline-grabbing item was the issue of the delineation of maritime boundaries between the two counties. The news once again put the spotlight on a lingering challenge that both sides continue to attempt to manage within their broader bilateral relationship.

Vietnam and the Philippines, Southeast Asian states and fellow South China Sea claimants, have long had a wide-ranging relationship. The delimitation of maritime boundaries remains a challenge the two sides have worked to manage.

The delimitation of maritime boundaries remains a complex challenge across Southeast Asia. A case in point, the maritime boundary treaty concluded between the Philippines and Indonesia in 2014 – which covered the delimitation of overlapping exclusive economic zones in the Mindanao Sea and Celebes Sea – took about two decades to negotiate.

The Vietnam-Philippines maritime boundary challenge in particular has been in the spotlight in recent years. Most notably, Malaysia and Vietnam made a rare joint submission to the Commission on the Limits of the Continental Shelf in 2009 where they extended claims to the seabed in the southern part of the South China Sea but agreed to pursue joint development in the disputed area. The Philippines fiercely objected that the submission may infringe on its own extended continental shelf, the boundaries of which remain unclear.

Vietnam had seen the joint submission as a broader effort to narrow lingering differences among Southeast Asian claimants in the South China Sea with the goal of presenting a more unified ASEAN position vis-à-vis China. Manila’s response was a sobering reminder of the limits of any bilateral agreement without the resolution of other remaining disputes between Southeast Asian states.

The likelihood of managing that issue seemed to have become even more bleak when Duterte came to power in 2016. Duterte’s attempted shift of Philippine foreign policy toward China and his downplaying of the case the Philippines had lodged against Beijing on the South China Sea seemed to remove a key point of convergence that had driven Vietnam-Philippine ties under the previous administration of Benigno Aquino III. The Vietnam-Philippines relationship was officially elevated to a strategic partnership just six months before Duterte came to power.

Nonetheless, both sides have continued their usual interactions and attempted to advance opportunities and manage challenges in their relationship, including in the maritime realm, in a quieter fashion. When Duterte and Phuc met previously at the 32nd ASEAN Summit in Singapore in April, they discussed the South China Sea dispute, the arbitral tribunal ruling, and issues within their security ties including in the maritime realm.

In October, the delineation of maritime boundaries was in the headlines again when Duterte met Phuc once more. The meeting came on the sidelines of the ASEAN Leaders’ meeting held in Bali, Indonesia. It also came just before a few active weeks on the South China Sea issue, with ASEAN set to hold its first maritime exercise with China and progress being sought by Beijing on a binding code of conduct on the South China Sea that has raised concerns about its content.

According to Duterte, during the meeting, the two leaders discussed the delineation of maritime boundaries when they met on October 11, among other agenda items. True to form, Duterte was not specific on any issue where details matter, saying upon his arrival back to the Philippines at the Davao International Airport, according to the Philippine News Agency (PNA), that “this has something to do with delineation of boundaries.”

That the maritime borders issue would have been discussed is no surprise. Vietnam in particular has been keen to continue to probe whether Southeast Asian states can further reduce their own differences so as to seem less divided relative to China and to move toward at least resolving part of a complex set of disputes. Duterte has not been afraid to occasionally tout measures the Philippines is taking with other Southeast Asian states even as it advances its ties with China in the maritime realm.

While the mention of the maritime boundary challenge resulted in quite a few headlines, neither leader mentioned any specifics in terms of next steps, whether in terms of negotiations or at least hints of some tangible progress. Indeed, Vietnamese accounts of the meeting were silent on the issue altogether. Duterte himself candidly noted that, “I told him [Phuc] that in due time, but we will take a longer period for we have to establish even our continental shelf limits.”

This, too, is not surprising. Duterte has been hesitant to undertake bold steps that would upset his embrace of China, and some sort of agreement with Vietnam would have fallen into that category, especially when Manila and Beijing are also looking to make progress on areas such as oil and gas development in the South China Sea. Hanoi has also been hesitant to publicly comment in the past about any ongoing efforts for fear of attracting too much unwanted attention from its large northern neighbor.

Nonetheless, as the Philippine-Vietnam relationship continues to evolve amid domestic and regional changes, the extent to which both countries can move forward in managing their maritime boundary challenge will be interesting to watch. Any indications of progress will be closely watched because they would have implications not just for the two countries, but for Southeast Asia and the wider Indo-Pacific as well.