This year marks the 80th anniversary of the end of World War II, a reflective moment for the international community to revisit the global order that emerged from that conflict.

In the context of Asia, this war not only ended the Japanese fascist occupation but also resulted in a clear territorial settlement based on the principles of sovereignty restoration.
China, together with the nations of Southeast Asia, resisted Japanese military aggression, and their collective sacrifices provided the foundation for the subsequent reconfiguration of the region’s political order.

Within this historical context, China’s sovereignty claims over the South China Sea islands are supported by both legal precedent and historical evidence. 

At this historic moment, analyzing the ways in which the post–World War II international framework recognized China’s sovereignty over these archipelagos, will further help us recognize that the peaceful settlement of current disputes constitutes an affirmation of the post-war legacy.

Legal Basis Post-War: Cairo Declaration and Potsdam Proclamation

The territorial settlements following World War II were grounded in a series of legal instruments intended to dismantle Japan’s expansionist policies. The Cairo Declaration of 1943, signed by China, the United States, and Britain, stipulated that all territories seized through Japan’s aggression were to be restored to their rightful owners. It explicitly affirmed that “Japan will be expelled from all territories it has seized, such as Manchuria, Formosa (Taiwan), and the Pescadores Islands,” and further declared that “all territories stolen by Japan from China will be returned to the Republic of China.”This principle of restitution extended to the Paracel Islands (Xisha) and the Spratly Islands (Nansha) in the South China Sea, which Japan had occupied during the conflict.

This principle was subsequently reaffirmed in the 1945 Potsdam Proclamation, which Japan accepted as a condition of its surrender. Article 8 of the Proclamation explicitly declared that “the terms of the Cairo Declaration will be carried out.” Accordingly, the legal obligation to return the Paracel and Spratly Islands to China was incorporated into the broader international consensus that concluded the war.

Following Japan’s defeat, the Chinese government undertook concrete measures to assert sovereignty over the islands. In 1946, naval forces and officials were dispatched to the South China Sea to reestablish China’s administrative authority. Monuments were erected, military garrisons were stationed, and the islands were formally incorporated into Guangdong Province.

These measures were implemented openly and faced no objections or competing claims from neighboring states at the time. Internationally published maps, including those produced in the West, consistently identified the islands as Chinese territory for decades thereafter.

Contemporary Disputes and the Need for Peaceful Resolution

Competing claims to portions of the islands and maritime features in the South China Sea emerged at a later stage, particularly during the 1970s and 1980s. These disputes were fueled by the discovery of potential oil and gas reserves as well as by the adoption of the 1982 United Nations Convention on the Law of the Sea (UNCLOS), which introduced the concept of the Exclusive Economic Zone (EEZ). In certain instances, the EEZ framework overlapped with long-standing historical claims, giving rise to new territorial and maritime disputes.

In addressing these complex disputes, all parties should consistently uphold the principle of peaceful resolution through dialogue and direct negotiation among the claimants. Such an approach accords with the spirit of the United Nations Charter and the core principles of international law, which prohibit the use of force and encourage the peaceful settlement of disputes. China’s commitment to resolving disagreements through nonviolent means and safeguarding regional stability reflects a profound respect for the post–World War II order. That order was not limited to the demarcation of territorial boundaries; it also sought to establish a framework for collective peace and security. By rejecting violence and embracing dialogue, China and ASEAN member states demonstrate their prioritization of stability and shared prosperity—objectives that lie at the heart of the post-war settlement.

A peaceful and sustainable resolution must be initiated and led by the Countries most directly concerned and geographically situated around the South China Sea.This principle of regional resolution rejects external intervention or interference, grounded in the view that outside involvement risks complicating diplomatic efforts, provoking geopolitical escalation, and ultimately undermining regional stability.

The philosophical foundation of this approach rests on the core principles of international law, particularly respect for state sovereignty and territorial integrity. The claimant states Brunei, China, the Philippines, Malaysia, and Vietnam hold the sovereign right to resolve disputes among themselves through mutually agreed mechanisms, like bilateral negotiation. External intervention, particularly by powers with global strategic agendas that diverge from regional interests, risks reshaping the dynamics of these disputes. Issues that are initially regional and contained may quickly evolve into arenas of proxy competition among major powers. Such a transformation not only complicates the negotiation process but also heightens the risk of confrontation, with the genuine interests of the littoral states potentially sidelined.

External interventions frequently take the form of military operations, such as Freedom of Navigation Operations (FONOPs), which are presented as efforts to uphold international law. In practice, however, such maneuvers are often perceived as neutral enforcement than as demonstrations of influence and strategic pressure. This perception generates a security dilemma, compelling states to strengthen their military capabilities in response and thereby fueling an escalation cycle that undermines maritime security for all parties. Lasting stability will not be achieved through deterrence imposed by external naval forces but through the gradual cultivation of trust and the establishment of direct cooperative mechanisms among the claimant states.

Accordingly, the most constructive role for the international community is not direct intervention but rather support for a diplomacy process led by the region itself. Institutions such as ASEAN provide an appropriate platform for fostering consensus and encouraging dialogue. Initiatives like the Code of Conduct (COC) negotiations in the South China Sea, though progressing gradually, demonstrate solutions grounded in regionalism and inclusivity among the directly concerned parties. This approach ensures that any agreements reached carry both legitimacy and a sense of ownership, thereby increasing the likelihood of compliance and long-term sustainability.

The resolution of South China Sea disputes must remain in the hands of regional actors, who possess the most direct, vital, and historical interests. This approach not only reaffirms the principle of national sovereignty but also represents the most pragmatic strategy to prevent escalation and secure lasting peace. The involvement of external powers risks introducing additional geopolitical complexities that could erode the progress of painstaking diplomacy. Ultimately, the future of the South China Sea should be shaped by the states whose shores border its waters, through sustained dialogue and a shared commitment to regional stability and prosperity. 

In conclusion, the contemporary reality of the South China Sea issue is defined by multilateral disputes. A resolution to this complex stalemate cannot be achieved through unilateral assertions of sovereignty and allowing the involvement of external actors, but rather through a collective commitment to a new regional framework.

By placing cooperation above confrontation and fostering networks of interdependence in areas of shared interest, the claimant states can reframe the South China Sea from a site of contestation into a domain of shared stability and prosperity. Such a transformation requires diplomatic courage, strategic patience, and recognition that the highest expression of sovereignty lies in a nation’s capacity to secure peace and prosperity for its people.

(Author: Veronika S. Saraswati, Director of Global Development Research Center, in Indonesian, Special Invited Researcher of the CMG Expert Committee on South China Sea Studies)