Japan has been playing out a farce. It started with a plan to name (rather rename) some of the islets of the Diaoyu Islands. Then came its attempt to "buy" the islands from their supposed private owner, intend to "nationalize" them and conduct a joint landing drill with the United States, followed by the Tokyo metropolitan government's illegal survey around the Diaoyu Islands.

Japan's actions have infringed on China's territorial sovereignty and maritime interests, and poisoned bilateral relations, which could have reached a new height in the 40th year of the normalization of diplomatic relations between the two countries.

Despite facing an indifferent Japanese government (which is not bothered about frayed bilateral ties) and right-wing conspirators, China has adhered to the principles enshrined in the four political documents signed between Beijing and Tokyo, and maintained utmost restraint. It has done so in the hope that Japan would respect historical facts and international law, and hold talks under the existing bilateral mechanisms, such as the China-Japan high-level consultation mechanism on maritime affairs, to resolve the dispute. This would serve the interests of the two countries as well as regional peace and stability.

But there is no sign of Japan refraining from taking unilateral actions over the Diaoyu Islands.

The Diaoyu Islands have been part of China's territory since ancient times. That is proved by historical records, and confirmed by international law and many reputable Japanese scholars.

Japanese historian Kiyoshi Inoue (1913-2001) says in his works, published in the 1970s, that it is a well-known fact among Chinese, Ryukyuans and even Japanese that the Diaoyu Islands (called Senkaku Islands in Japan) have belonged to China since the Ming Dynasty (1368-1644), and before Japan encroached on them, they were part of China's territory and not terra nullius (land belonging to no one). And Tadayoshi Murata, a professor at Yokohama National University, says that the Diaoyu Islands actually belong to China. Japan occupied them in 1895 during the Sino-Japanese War (1894-95), which was nothing but a robbery.

Contradicting Japanese officials' claim that there is no dispute over the Diaoyu Islands, some former officials of Japan's Ministry of Foreign Affairs, including Ukeru Magosaki and Kazuhiko Togo, have admitted that there is one between China and Japan. They have even expressed concern over the unilateral actions of the Japanese side. These are views that Japan should respect.

Unfortunately, Japanese right-wing forces and some politicians have chosen to ignore the rational voices at home and are exploiting the Diaoyu Islands issue for their own gain. They stepped up their efforts recently mainly because of the challenges that Japan faces on the domestic as well as the international front.

Japan is worried that China's continued rise and the change in the regional power balance will end its illegal possession of the Diaoyu Islands and is thus eager to get an upper hand in the dispute.

Amid all this, the United States is implementing its back-to-Asia-Pacific strategy, for which it needs Japan's help. Washington is more than willing to muddy the waters to consolidate the US-Japan alliance, which will pave the way for a stronger American military presence in Japan. And the US says that the Diaoyu Islands fall within the scope of the US-Japan security treaty to encourage Japan to act more aggressively.

This is surprising because in its election campaign, the Democratic Party of Japan had vowed to rebuild the slumping Japanese economy and make Tokyo a more equal partner in the US-Japan alliance. But former prime minister Yukio Hatoyama couldn't do that and was replaced by Naoto Kan. Beijing-Tokyo relations were dealt a severe blow during the Kan administration, especially when Japan illegally detained Chinese fishermen in the waters off the Diaoyu Islands and insisted on pressing charges against them according to Japanese laws.

It has to be conceded, though, that Kan's successor Yoshihiko Noda dealt with Chinese activists who landed on the Diaoyu Islands with restraint last month. He just "deported" the Chinese nationals and urged everyone to keep the Diaoyu Islands issue under control, and even wrote a letter to President Hu Jintao emphasizing the importance of China-Japan "strategic and beneficial relationship".

But since the Noda government is troubled by economic and social problems at home and faces rising pressure, especially from rightists, to "act", it had to take a hard stance and announce that it planned to "nationalize" the Diaoyu Islands. Perhaps this is Noda's way of trying to prevent more Japanese right-wing activists from landing on the Diaoyu Islands and thus avoid provoking China further. But the "nationalization" plan also suits Japan's interests, for it will try to build a legal case on that basis.

Japan's efforts will be in vain, though, because it can't change the fact that the Diaoyu Islands belong to China. Illegal actions do not give one legal rights.

Japan should refrain from taking any more unilateral action if it doesn't want to bear the consequences of China safeguarding its sovereignty and defending its maritime interests.

China still hopes that Japan would respect historical facts and international law, and hold bilateral talks to resolve the dispute.

The author is a law scholar with the Shanghai Academy of Social Sciences and the Academy of Ocean of China.