The Philippines is a key party to the South China Sea disputes, claiming jurisdiction over waters within 200 nautical miles of its coast, while also asserting sovereignty over Scarborough Shoal in the Zhongsha Islands and certain features in the Spratly Islands. Since the 1960s, the Philippines’ policy actions concerning the South China Sea disputes can be summarized as “one main thread and three measures”: focusing on the goal of maritime expansion; illegally occupying certain islands and reefs through military and gray-zone tactics; strengthening its claims through domestic legislation and by resorting to third-party mechanisms; and seeking U.S. support to consolidate and expand its maritime claims. In June 2024, the Philippines unilaterally submitted a delimitation application to the United Nations Commission on the Limits of the Continental Shelf for areas in the South China Sea beyond 200 nautical miles. The area covered is much larger than its exclusive economic zone, marking yet another attempt by the Philippines at maritime expansion. Shortly after Marcos took office, in addition to maintaining its conventional policy approaches, the Philippine government’s stance on the South China Sea disputes began to show signs of “radicalization.” Some measures have even violated the basic norms of modern international relations, while others have departed entirely from the traditional trajectory of Philippine foreign policy—reflecting a shift from being “driven by national interests” to being “driven by emotional impulses.” The Philippines’ tendency toward “radicalization” reflects the complex struggles among political families, bureaucratic circles, and elite groups, while also being closely linked to the strong influence of the United States. Shaped by domestic political currents and the structure of political groupings, this trend is unlikely to be reversed with a change of leadership. At the same time, it faces compounded challenges arising from both regional dynamics and bilateral relations.