Every time the Philippines sends fresh troops to its lonely outpost in Ayungin Shoal or delivers food, water, and fuel to BRP Sierra Madre, Chinese vessels are expected to shadow, block, and prevent local troops from completing their rotation and resupply missions.

It is interesting to note that China did not do the same risky maneuvers when the Philippines made similar rotation and resupply missions in other occupied features in the South China Sea.

Is China doing the same in areas occupied by Malaysia and Vietnam?

Perhaps, not. It’s only in Ayungin Shoal where China is asserting its sovereignty claim in the disputed waters.

China has been anxiously waiting for BRP Sierra Madre, a World War II vintage naval transport vessel, to collapse as rust continues to envelope and eat the ship’s structure.

The Philippines has refused to retire BRP Sierra Madre, a symbol of its sovereign claims on the South China Sea.

Keeping the vessel active would drag the United States, a long-time treaty ally, to the country’s defense in case China decides to forcibly remove the vessel under the 1951 Mutual Defense Treaty.

Thus, for the last 10 years, the military has been repairing BRP Sierra Madre to keep it as a proud symbol of defiance to China’s illegal and expansive claims in the South China Sea.

China knew about the repairs so it has been trying to stop the Philippines from bringing in construction materials to BRP Sierra Madre.

That is how simple the situation in BRP Sierra Madre is.

When the Philippines was upgrading its military facilities on Thitu Island or Pagasa Island, China tried to put up a blockade around the feature, sending dozens of vessels to make it difficult for the local military to bring in materials to build a secured port and repair the runway.

China was trying to prevent small improvements on Pagasa Island but it had built artificial islands on the features it occupies in the Spratly chain of islands.

China will not stop its assertive actions in the South China Sea, escalating tensions and risking miscalculations and accidents that could lead to a shooting war.

In 2016, the Philippines clearly won an international legal ruling, which repudiated China’s nine-dash-line claim on almost the entire South China Sea.

Beijing did not only ignore and refuse to recognize the ruling of the Permanent Court of Arbitration in The Hague, it issued a new map showing a 10-dash-line, claiming Taiwan which it considers a renegade province.

The only way China will responsibly behave in the disputed waters is to adopt a rules-based and legally binding Code of Conduct in the South China Sea.

For more than a decade now, China and Asean have been negotiating a formal Code of Conduct in the South China Sea.

In Phnom Penh in 2002, the two sides agreed on a landmark political document to ease tensions in the disputed area — the Declaration on the Conduct of Parties in the South China Sea (DOC).

But Asean wanted a rules-based and legally binding agreement to stop China from its coercive activities in the disputed waters.

Indonesia proposed to include in the Code a provision to stop China from excessive reclamation and building artificial islands and militarizing the features.

Vietnam suggested preventing any party to the Code from blocking any resupply mission in the Spratlys.

China wanted to delete Indonesia’s proposal but has remained silent on the Vietnamese proposal.

It countered a proposal for any party to notify all claimants on an impending military drill in the area, especially if an outside power is involved.

Asean rejected it but compromised to make the notification voluntary on the part of any party holding a drill with outside power.

The United States, Australia, and Japan have been regularly conducting freedom of navigation and overflights in the disputed areas in South China Sea.

In the future, they plan to hold joint sails with the Philippines to challenge China’s sovereignty claims in the area.

Since 2017 when a Code of Conduct framework was agreed in Manila, there have been two readings of the proposed Code.

The third reading will commence in October when the Asean-China Joint Working Group (JWG) on the implementation of the Declaration of Conduct of Parties in the South China Sea (DOC) holds its 42nd meeting in China.

More than two decades after the DOC was agreed, Asean and China have struggled to come up with a formal COC.

China is stalling the COC. It has been resisting to make the formal COC a legally binding document.

It wanted the COC to remain a political document similar to the DOC.

China is afraid it will no longer be able to assert its sovereignty claim. The document will prevent Beijing from conducting illegal and coercive activities in the South China Sea if it agrees to a rules-based and legally binding agreement.

A formal COC will ease tensions and prevent miscalculations and accidents in the disputed waters.

It will be the only way for China to behave responsibly in the disputed waters, stopping it from preventing rotation and resupply missions to Ayungin Shoal.

Asean must put extra pressure on China to agree as soon as possible to a Code of Conduct and transform one of the region’s flashpoints into an area of stability and cooperation.

Asean and China must come to an agreement now to adopt a formal Code of Conduct.