The decades-long negotiations on a code of conduct in the South China Sea may finally come to an end this year. Several parties involved, including China and the Philippines, have expressed confidence in reaching a final conclusion to the proposed set of rules in the contested waterways in the coming months.

In March, Beijing signalled its hope of concluding negotiations with the Association of Southeast Asian Nations by the end of the year while Manila has repeatedly expressed its intention to see the negotiations concluded during its chairmanship of Asean this year.

But relations between Beijing and Manila have been precarious and unstable in recent years. Can the two insulate negotiations from their maritime and political frictions, or will these become yet more obstacles to the conclusion of the code of conduct?

Much will depend on how Beijing and Manila manage two key issues of 2026: the 10th anniversary of the 2016 South China Sea arbitration ruling, and the persistent distrust between both countries’ frontline maritime forces.

China has never accepted the July 12, 2016, ruling by the tribunal of the Permanent Court of Arbitration in The Hague, rejecting it immediately as “null and void” with “no binding force”. Beijing continues to reiterate its non-acceptance of the ruling even as Manila marks the anniversaries over the years. As the 10th anniversary approaches, both countries can be expected to enter another period of political tension and high-profile clashes in the South China Sea.

But the relationship was not always so. The 2016 election of Rodrigo Duterte in the Philippines led to a stabilisation as his administration gravitated towards China and away from the United States.

In October that year, Duterte visited China and met President Xi Jinping. By the following May, both countries had established a bilateral consultation mechanism for their South China Sea issues. As relations improved, both downplayed the ruling.

On July 13, 2017, responding to a positive Philippine statement on the first anniversary of the arbitration award, China’s foreign ministry said the authorities “applaud” and “support” the Philippines’ independent foreign policy. By the second anniversary in 2018, the ruling did not even merit a mention in the foreign ministry’s regular press conference.

But since Ferdinand Marcos Jnr took office in the Philippines in 2022, relations with China have seen a rapid downward spiral. While it is unrealistic to expect a similar handling of the arbitral ruling, the Duterte period did show a possibility where both countries were willing and able to contain any fallout from the ruling.

If Beijing and Manila today are still willing to make the effort they did 10 years ago, it would not only change the current course heading towards more acute confrontation, but also shelter the South China Sea’s code of conduct negotiations from any antagonistic symbolic gestures.

The second challenge is the growing hostility and distrust between the frontline maritime actors of China and the Philippines, namely their respective coastguards and navies. The relationship is not one shaped by high diplomacy, but one defined by frequent and often dangerous close encounters at sea. In less than four months in 2026, both sides have engaged in at least eight maritime clashes.

Repeated hostile confrontations have created a deep-rooted institutional suspicion. The recent dispute over China’s extension of humanitarian aid to a Philippine fisherman was telling. Last December, China reported its navy vessel had provided food and water to a Filipino fisherman near Scarborough Shoal who had been “stranded for three days due to engine failure”. The Philippine coastguard “acknowledged” the aid but also warned against the incident being “exploited as propaganda by China”, pointing out the fisherman had been adrift for “less than 24 hours” rather than days.

From China’s perspective, this was an effort to inject a more positive dimension to a relationship fraught with distrust and hostility. But in the eyes of the Philippine forces, it was aimed at polishing China’s image and advancing its narrative.

The problem has become more visible in recent months. Since October, the two countries have been negotiating a coastguard cooperation agreement, led by the respective foreign affairs ministries. Last month, China’s ambassador to the Philippines Jing Quan said the deal was “95 per cent complete”. Such progress would have been hailed as a breakthrough if the Philippine coastguard did not quickly distance itself, denying any participation in the “crafting” of this agreement with China.

This episode exposed a divergence between Philippine’s coastguard and foreign affairs department. While the department strives to cultivate trust, the coastguard appears to be deeply unwilling to endorse an agreement that might be regarded as not “standing up” to China. For the coastguard authorities, it would seem that safeguarding national interest would exclude the possibility of cooperation.

Should such suspicion and distrust persist, it will keep producing headwinds in the face of any effort to maintain a constructive relationship. Any attempt to foster a positive climate for the South China Sea code of conduct negotiations will also meet renewed and constant challenges.

Both Beijing and Manila must set aside their deep-rooted hostility and exercise self-restraint, not only through diplomatic channels, but also through daily operations at sea. If both sides fail to exercise that restraint, 2026 might eventually be remembered not as the year of the long-awaited conclusion of the code of conduct, but as another moment when opportunity was lost to distrust.

Author: Mengzhen Liu, Assistant Research Fellow at Huayang Center for Maritime Cooperation and Ocean Governance.

This article was originally published on SCMP. Read the original article at: https://www.scmp.com/opinion/asia-opinion/article/3349697/without-restraint-beijing-and-manila-cant-deliver-south-china-sea-code