Im no expert on the Spratley islands but it looks like part of the R.P to me!!
The Chinese are not interested in negotiating anything with any other claimants of the "disputed" territory and quite content to fire live rounds from its warships over the heads of Filipino fishermen in Western Palawan.
I dont think they would have taken these measures in the 80`s purely because the huge deterrent that the Yank bases provided here.. Most ordinary Filipino`s I have spoken to over the years loved the fact that the U.S had a large presence here then and many were shocked that they left after Pinatubo exploded..
The U.S remains the R.P`s number one ally and they will need to count on them more and more as the Chinese bullying becomes more intense because of their greed for other countries resources.