2. Japan's occupation of Diaoyu Islands is illegal and invalid.

1) Japan started to encroach on Diaoyu Islands in the late 19th century.

Immediately after seizing Ryukyu in 1879, Japan began to extend its reach to China's Diaoyu Islands. Tatsushiro Koga, a Japanese explorer, landed on Diaoyu Islands in 1884, claiming that they were terra nullius. Between September and November 1885, the Japanese government secretly dispatched three facts-finding missions to the islands which concluded that, these "terra nullius" islands were, in fact, the same Diaoyu Tai, Huangwei Islet and Chiwei Islet that were recorded in the Records of Messages from Chong-shan and well known to imperial title-conferring envoys of the Qing court on their voyages to Ryukyu.

Between 1885 and 1893, the then authorities in Okinawa Prefecture three times submitted a written request to the Japanese government that Diaoyu Islands, Huangwei Islet and Chiwei Islet be put under its jurisdiction and boundary markers erected. China reacted to this. On September 6, 1885 (July 28 in the 11th year of the reign of Emperor Guangxu of the Qing Dynasty), the Chinese newspaper Shen-pao (Shanghai News) reported: "Recently, Japanese flags have been seen on the islands northeast to Taiwan, revealing Japan's intention to occupy these islands." China's reaction made the Japanese government think twice before taking any further action. The then Japanese Foreign Minister Inoue Kaoru expressed his concern in his letter to Yamagata Aritomo, the Japanese Minister of Internal Affairs, "At present, any open moves such as placing boundary markers are bound to alert the Qing imperial court. Therefore, it is advisable not to go beyond field surveys and detailed reports on the shapes of the bays, land and other resources for future development. In the meantime, we will wait for a better time to engage in such activities as putting up boundary markers and embarking on development on the islands." In light of this, the Japanese government rejected the requests from Okinawa Prefecture. These facts have all been clearly recorded in Japan Diplomatic Documents. All this shows that Japan intended to occupy Diaoyu Islands, knew full well China's sovereignty over the islands, and refrained from acting impetuously only for fear of reaction from China.

2) Japan illegally grabbed Diaoyu Islands through the First Sino-Japanese War.

Japan started the first Sino-Japanese War in July 1894. Towards the end of November 1894, Japanese forces seized the Chinese port of Lüshun (then known as Port Arthur), virtually ensuring the defeat of the Qing court. Against this backdrop, the Japanese Minister of Internal Affairs Yasushi Nomura wrote to Foreign Minister Mutsu Munemitsu on December 27 that "I am writing to discuss with you about setting up boundary markers in Kuba-jima (Huangwei Islet) and Uotsuri-jima (Diaoyu Islands)". "The circumstances have now changed and it is possible to submit this issue to the cabinet for a reconsideration." Mutsu Munemitsu expressed his support for the proposal in his reply to Yasushi Nomura on January 11, 1895. The Japanese government secretly passed a resolution on January 14 to place Diaoyu Islands under the jurisdiction of Okinawa Prefecture. But in fact, at the time, the Japanese government neither erected any boundary markers on Diaoyu Islands, nor did it include in the Japanese Emperor's decree on the geographical scope of Okinawa Prefecture. On April 17 the same year, China was forced to sign the unequal Treaty of Shimonoseki with Japan, under which the entire island of Taiwan, together with all its affiliated islands, including Diaoyu Islands, were ceded to Japan. Thereafter, Japan imposed colonial rule over Taiwan and its affiliated Diaoyu Islands for 50 years from the signing of the unequal treaty until Japan's surrender at the end of World War II.

3) Diaoyu Islands were returned to China after World War II.

On December 1, 1943, China, the US and the UK issued the Cairo Declaration, which stated in explicit terms that "all the territories Japan has stolen from the Chinese, such as Manchuria, Formosa (Taiwan) 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." In July 1945, China, the US and the UK issued the Potsdam Proclamation (The Soviet Union signed the Proclamation in August that year) which stated in Article 8: "The terms of the Cairo Declaration shall be carried out and Japanese sovereignty shall be limited to the islands of Honshu, Hokkaido, Kyushu, Shikoku and such minor islands as we determine." On August 15, 1945, Japan accepted the Potsdam Proclamation and surrendered unconditionally. On September 2, the Japanese government pledged to faithfully fulfill the obligations enshrined in the provisions of the Potsdam Proclamation in Articles 1 and 6 of the Japanese Instrument of Surrender. These documents all testify to the fact that Taiwan and its affiliated Diaoyu Islands should be simultaneously returned to China.

4) Backroom deals between Japan and the United States over Diaoyu Islands are illegal and invalid.

On September 8, 1951, Japan, the United States and a number of other countries signed the Treaty of Peace with Japan (commonly known as the Treaty of San Francisco) with China excluded from it, which placed the Nansei Islands south of the 29th parallel of north latitude under United Nations' trusteeship, with the United States as the sole administering authority. On September 18, 1951, Zhou Enlai, the then Chinese Premier and Foreign Minister, made a solemn statement on behalf of the Chinese government that the Treaty of Peace with Japan signed in San Francisco was illegal and invalid and could under no circumstances be recognized by the Chinese government since China had been excluded from its preparation, formulation and signing. The islands placed under the administration of the United States in the Treaty of Peace with Japan did not include Diaoyu Islands. However, on December 25, 1953, the United States Civil Administration of the Ryukyu Islands (USCAR) issued Civil Administration Proclamation No. 27 defining the "geographical boundary lines of the Ryukyu Islands", arbitrarily expanding its jurisdiction to include China's Diaoyu Islands. There were no legal grounds whatsoever for the United States to take this action.

On June 17, 1971, Japan and the United States signed the Agreement Concerning the Ryukyu Islands and the Daito Islands (Okinawa Reversion Agreement), which provided that any and all powers of administration over the Ryukyu Islands and Diaoyu Islands would be "reverted" to Japan. The Chinese government and people, including overseas Chinese, expressed their strong opposition to the backroom deal between Japan and the United States over Diaoyu Islands. The Chinese Ministry of Foreign Affairs issued a statement, fiercely condemning the US and Japanese governments for wilfully including China's Diaoyu Islands into the territories to be returned to Japan in the Agreement. The statement pointed out that "the agreement was a blatant violation of Chinese territorial sovereignty and would not be tolerated by the Chinese people."

In face of this, the United States administration had to make clarifications. It publicly stated that "the United States believes that a return of administrative rights over those islands to Japan, from which the rights were received, can in no way prejudice any underlying claims. The United States cannot add to the legal rights Japan possessed before it transferred administration of the islands to us, nor can the United States, by giving back what it received, diminish the rights of other claimants. The United States has made no claim to Diaoyu Islands and considers that any conflicting claims to the islands are a matter for resolution by the parties concerned." In the same year, when presenting the Okinawa Reversion Agreement to the United States Senate for ratification, the United States Department of State stressed that the United States took a neutral position with regard to the competing Japanese and Chinese claims to the islands, despite the return of administrative rights over the islands to Japan. The United States Department of State has since restated its position even in recent years, stating that "the United States does not take a position on the question of the ultimate sovereignty of the Senkaku Diaoyu Islands. This has been our longstanding view. We expect the claimants will resolve this issue through peaceful means."

The facts have shown that both the Japanese stealing of Diaoyu Islands from China in the late 19th century and the backroom deals by the US and Japan concerning Diaoyu Islands in 1970s are acts of grave violation of China's territorial sovereignty. They were illegal and invalid, did not and cannot in any way change China's ownership of Diaoyu Islands.