evidence: Since November last year, Vietnam has accelerated the expansion of its outposts in the Spratly Islands, according to a report published earlier this month by the Asia Maritime Transparency Initiative, or AMTI, at the Washington-based Center for Strategic and International Studies. [...] Vietnam and the Philippines have been locked in a decadeslong territorial dispute with China over the South China Sea and its islands despite a ruling in 2016 by the Permanent Court of Arbitration in The Hague that dismissed China’s claim to most of the sea. That claim infringes on the exclusive economic zones of several coastal states. [...] Hanoi and Manila have overlapping claims to features in the Spratly chain, but incidents between the two countries have been rare, while bilateral ties were strengthened during President Ferdinand Marcos’ state visit to Hanoi earlier this year. The two countries agreed to increase coast guard cooperation.