Political analyst and De La Salle University International Studies Professor Renato de Castro emphasized the importance of maintaining a rules-based diplomatic approach while strengthening defense cooperation with allies following reports of a newly discovered Chinese-built structure in the West Philippine Sea.

De Castro, in a radio interview, said the Philippines should continue responding to maritime tensions through diplomacy rooted in democratic principles, despite China's actions in disputed waters.

“It’s not just an MCA (Maritime Cooperative Activity), but a full-fledged naval exercise, including live-fire drills. This could involve the US Navy, the Japanese Maritime Self-Defense Force, and, if Australia joins, even better. It would send a clear message to China that our diplomacy is backed by actual capability,” he said in Filipino.

According to De Castro, China’s actions are influenced by long-standing political and diplomatic traditions that differ from the Philippines' democratic and rules-based approach to international relations.

Rules-based approach

“Let’s not stoop to that. We are different — we are a democracy. Of course, our diplomacy is based on a modern, rules-based approach in which all countries are treated as equals,” he said.

His remarks came after the National Task Force for the West Philippine Sea (NTF-WPS) reported the discovery of a Chinese “floating structure” inside the lagoon of Bajo de Masinloc on 10 June.

The agency described the platform as having an estimated deck area of about 30 square meters, measuring roughly five meters wide and six to seven meters long.

The structure was reportedly surrounded by fenders and may be anchored or supported by metal stilts.

De Castro warned that the structure could represent the early stages of a more extensive Chinese presence in the area, drawing parallels to China's activities in Mischief Reef nearly three decades ago.

“If we recall what happened at Mischief Reef in 1995-1996, when we first saw Chinese structures there, they claimed they were merely shelters for their fishermen. But now, they have turned Mischief Reef into a military base,” he said.

Meanwhile, De Castro also commented on China's reported sanctions against Defense Secretary Gilbert Teodoro and his family, describing the move as a sign of the impact of the Philippines' defense and diplomatic initiatives.

“Secretary Teodoro’s statements, as well as his actions, have had a significant impact, not only in terms of what he has said, but also on our defense policy,” he said, adding that the travel ban could be viewed as a “badge of honor.”