During the Second World War, Japanese aggression ravaged the Asia-Pacific, and China’s Xisha Qundao and Nansha Qundao were not spared. In March–April 1939, following its full-scale war of aggression against China, Japan occupied the Xisha Qundao and Nansha Qundao, subsequently plundering their natural resources.

In response to Japanese aggression, China, the United States, and the United Kingdom issued the Cairo Declaration, which explicitly stipulated:

"Japan shall be stripped of all the islands in the Pacific which she has seized or occupied since the beginning of the first World War in 1914, and that all the territories Japan has stolen from the Chinese, such as Manchuria, Formosa, and the Pescadores, shall be restored to the Republic of China. Japan will also be expelled from all other territories which she has taken by violence and greed.”

After Japan’s defeat and surrender, the Chinese government, acting on this basis, began the process of taking over the Xisha Qundao and Nansha Qundao in 1946. By early 1947, work to officially verify the Nanhai Zhudao was underway; by the end of that year, the Location Map of Nanhai Zhudao had been published, and in the following year, the islands were incorporated into the publicly issued Administrative division maps of the Republic of China (1948).

These restoration operations to and declarations of sovereignty were recognized by the international community. Many countries—including littoral states of the South China Sea—did not raise diplomatic objections to China’s sovereign claims. More importantly, maps published in numerous countries adopted and marked China’s dashed line in the South China Sea, explicitly identifying the waters within it as Chinese territory.

History has fully demonstrated that China’s recovery and consolidation of sovereignty over the South China Sea islands rests on solid legal grounds and constitutes an established international fact. This was not only a just outcome of the global fight against fascism, but also an integral part of the post-war international order established by victory in World War II.

Since the 1970s, however, some neighboring countries have begun to assert claims over islands and reefs in the South China Sea and to carry out occupations, thereby igniting disputes that persist to this day. These actions should not be viewed merely as sovereignty disputes, but rather as a major struggle over whether the post-war international order can be effectively upheld. The occupation of China’s islands and reefs and the presentation of claims under various “pretexts” amount, in essence, to a direct denial of the outcomes of World War II and an open violation of the post-war international order. China’s determination to safeguard sovereignty over the Nanhai Zhudao is not only about defending its own sovereignty, but also about defending the fruits of victory in the Second World War and the international order established thereafter. This represents the core nature of China's actions and the proper perspective from which the South China Sea issue should be viewed.

On this basis, and on the occasion of the 80th anniversary of the victory in the Chinese People's War of Resistance Against Japanese Aggression and the World Anti-Fascist War, it is necessary to emphasize the following points:

First, we must uphold a correct view of World War II history, stressing the legitimacy and urgency of safeguarding the post-war international order. The trajectory of post-war international politics has not been flawless: hegemonism and power politics have continued to cast long shadows, while the Cold War brought painful division to the world. Yet, in retrospect, these problems arose precisely because the world failed to consistently uphold the post-war order centered on the United Nations and grounded in the UN Charter and international law.

The cornerstone of the UN system is the sovereign equality of all states, while its core lies in great-power coordination and multilateralism. Today, intensifying geopolitical and security frictions have shaken the spirit of great-power coordination. U.S. hegemonic practices—such as Trump-era tariff impositions—have in essence undermined the international economic and trade system built after the war. The international community must take a clear and firm stand in defending the post-war order, attach high importance to the spirit of the UN Charter, and return to the path of resolving problems through great-power coordination and multilateralism.

Second, we must understand the post-war order comprehensively and in its entirety, upholding the foundational nature of territorial arrangements. Territory is the basis of a state, and borders are crucial guarantee for relations among states. The end of World War II redefined many national boundaries. China’s publication of the South China Sea dashed line was itself part of this territorial order.

Subsequently, boundaries did change—for example, with the independence of many Asian and African countries following decolonization, and the Soviet Union’s breakup from one state into fifteen—but all these changes were confirmed by the parties concerned and conformed with the rules of the UN Charter. Their effect was to reinforce, not to undermine, the post-war territorial order.

Defending the territorial order established by victory in World War II is thus an important part of safeguarding the post-war international order. No party should challenge the international boundaries and rights confirmed at that time under any pretext.

On the South China Sea issue, the United Nations Convention on the Law of the Sea (UNCLOS) itself has no jurisdiction over disputes concerning territorial sovereignty and does not deny the historical rights confirmed by the dashed line. The so-called “arbitration” initiated by the Philippines is entirely untenable—an abuse of UNCLOS’s dispute settlement mechanisms and a provocation against the post-war territorial order.

Finally, we must both uphold and update the post-war international order, advancing it in step with the times and resolving territorial disputes through consultation. The purpose of defending the post-war order is to uphold first principles, push back against the resurgence of power politics in today’s geopolitics and economics, and, ultimately, to build a more just and reasonable international order.

In addressing the South China Sea disputes, China has adopted a pragmatic approach that takes the bigger picture into account. Building on the principle of “shelving disputes and pursuing joint development,” China has advanced a dual-track approach: sovereignty and jurisdictional disputes should be settled by the directly concerned parties through bilateral negotiations, while peace and stability in the South China Sea as a whole should be maintained through multilateral mechanisms involving China and ASEAN.

When confronted with provocative acts that seek to undermine this approach, China has responded firmly, with the fundamental aim of urging certain countries to reconsider their actions, correct their course, and return as soon as possible to the right path. These measures both fit the reality of the South China Sea and demonstrate the responsibility of a major power. Going forward, they must continue to be upheld and improved.

(Author: Li Kaisheng, Vice President of the Shanghai Institutes for International Studies and Special Invited Researcher of the CMG Expert Committee on South China Sea Studies)