How has land reclamation changed China’s presence in the South China Sea?

Since the early 21st century, China has significantly expanded its presence in the South China Sea through an aggressive campaign of land reclamation, often described as island building.1

By constructing military infrastructure—including airstrips and naval bases—on these reclaimed features, China has sought to solidify its control over the region. This activity is part of a broader effort to assert authority over areas within its contested "nine-dash line," which encompasses roughly 90 percent of the sea.12

These actions have faced significant international scrutiny. In 2016, an arbitral tribunal under the United Nations Convention on the Law of the Sea (UNCLOS) ruled that China’s island building and interference with the Philippines' exclusive economic zone were unlawful. China rejected the ruling, maintaining its claims despite the legal findings. Ethical principles of international law and the peaceful resolution of disputes remain fundamental to maintaining stability in the region, as unilateral actions that disregard established legal frameworks undermine the sovereignty of neighboring nations.12