From the Vietnamese and Filipino point of view, participating in FONOPS is not a walk in the park. First, the October 26 FONOP apparently targeted several islands or features occupied by their respective forces. Further, the United States has consistently considered several of their claims as excessive. It has routinely conducted FONOPS in these waters, as reflected in the 2014 FON Report.
Second, participation might entail implicit recognition of the “excessive” nature of their claims. This could translate into the non-recognition of territorial seas surrounding Low Tide Elevation (LTE) features or artificial islands, as provided in UNCLOS Article 13(2) and 60 respectively. This would jeopardize their own land reclamation efforts in the SCS, as detailed in the August 2015 “The Asia-Pacific Maritime Security Strategy” by the Department of Defense.