The East Sea in 2025: China’s Policies and Activities

Abstract

This article examines the key features of China’s policies and behaviour in the South China Sea in 2025, highlighting a pattern of both continuity and adjustment. It argues that Beijing continues to pursue its grey-zone strategy through close coordination among the navy, coast guard, and maritime militia to consolidate “actual control” at sea. At the same time, China has expanded the militarisation of its maritime outposts and intensified the use of legal instruments to “legalize its claims,” a trend that has been consistently reinforced since 2016. However, 2025 also witnesses several notable shifts: an escalation in on-the-ground grey-zone activities; the use of environmental discourse as a tool to legitimize sovereignty claims and expand the exercise of jurisdiction; and China’s accelerated adoption of advanced technologies, surveillance systems, and emerging operational capabilities to dominate strategic maritime spaces-especially in the undersea domain amid growing competition.