WASHINGTON, DC—A senior analyst of a US-based think-tank has warned the Philippines against entering into joint exploration of South China Sea resources with China, saying it might compromise Philippine sovereignty.

Speaking to Filipino journalists, RAND Corporation's Derek Grossman said the Philippines should weigh the costs and benefits of a joint exploration with China in Reed Bank in the disputed waters. While it may smoothen relations, Grossman said, it would be done on Beijing’s terms.

"What we’re seeing is joint exploration for energy resources probably’s not gonna work out. It will be on Beijing’s terms if anything,” Grossman said.

"My view is that [President Rodrigo] Duterte wants to be able to defend Philippine sovereignty but he can’t do it and so what he is trying to do is his half-measures to try [to] get more comfortable with China and have China get more comfortable with the Philippines so that maybe at some point in the future, the Philippines would maintain some measure of sovereignty but joint exploration is not gonna get to that point," he said.

He added that "joint explorations are still under the auspices of the Chinese."

"They tell you when, where and how to do it. It’s not gonna eventually lead to more Philippine sovereignty.”

The Philippines earlier this year agreed to a joint exploration with China in the resource-rich disputed waters even as Beijing continued to assert indisputable sovereignty over nearly all of South China Sea, including parts of the Philippines' exclusive economic zone.

Grossman said entering into joint exploration with China is like rewarding it for ignoring the July 2016 ruling of the Permanent Court of Arbitration, which invalidated Beijing’s sweeping nine-dash claim over South China Sea.

China reiterated its rejection of the ruling in August.

"The costs are you are no longer stating unambiguously that this territory is that of the Philippines and that’s what is struggling to me about it," Grossman said.

"Need I remind you guys: Permanent Court of Arbitration ruling in 2016 was pretty clear at least in that particular case that the Philippines had the correct argument in the South China Sea and China ignored it. And there have been no repercussions from Manila or frankly from anyone else for China’s continued ignorance of that ruling. When doing joint exploration, that’s almost like a reward for something you have not received reciprocation for."

What should the Pentagon and the Philippine defense establishment do to contain Chinese aggression in the South China Sea?

RAND Corporation Senior Policy Researcher John Gordon IV recommended taking a "consistent front" against the Chinese by maintaining a close defense partnership and giving the US more access to Philippine bases.

Gordon said the potential of the Philippines-US Enhanced Defense Cooperation Agreement (EDCA) is not being maximized.

"Take a consistent front against the Chinese and I think having a common message from United States and the Philippines is probably a very important thing to do. I think a lot of people in the US military they are very interested in the amount of access the American military is gonna get in the Philippines. You know, that’s been an on-again, off-again issue of how much access the US will get to bases in the Philippines, permanent or temporary bases,” Gordon said.

The US has several times hit Chinese military buildup and reported aggressions in the South China Sea, asserting freedom of navigation in the vital waterway. Beijing has, meanwhile, criticized US meddling.

RAND Corporation Political Scientist Bonny Lin recommended maintaining strong Philippine-US relationship, investing in capabilities and maritime domain awareness.

This amid a cozying of ties between Manila and Beijing under Duterte, who has deviated away from traditional allies, including the US, a long-standing defense partner.

"I’m also saying looking at particular types of military capabilities that will enable you to better be able to understand and... patrol your claims in the region, maritime domain awareness capabilities are particularly high on that list,” Lin said.

Lin said relations between the Philippines and US are on “solid track right now.”

RAND Corporation is a think-tank that describes itself as a nonprofit institution that “helps improve policy and decision making through research and analysis.” It is known to advise US government officials, including the defense establishment.