Officials in Beijing might argue that a monitoring station doesn’t violate the 2002 Declaration on the Conduct of Parties in the South China Sea that it signed with the Association of Southeast Asian Nations (ASEAN), which is being chaired by the Philippines this year, said Jonathan Spangler, director of the South China Sea Think Tank in Taipei.

That accord only prohibits occupying so far uninhabited land features in the disputed sea,

“Building an environmental monitoring station on Scarborough Shoal could theoretically be done without inhabiting the feature, but that would not make the action seem any less provocative to rival claimants or other major stakeholders,” Spangler said.