The Diaoyu Islands are a group of uninhabited islands located roughly due east of mainland China, northeast of Taiwan, west of Okinawa Island, and north of the southwestern end of the Ryukyu Islands. They are currently controlled by Japan, which calls them Senkaku Islands. Both China and Taiwan claim sovereignty over the islands.
Ex-ambassador Uichiro Niwa calls Japan too quick to buy Diaoyus
Tokyo's former ambassador says he questioned move that helped escalate tensions with Beijing
Julian Ryall in Tokyo
Uichiro Niwa, Tokyo's former ambassador to Beijing, has criticised the Japanese government for rushing into the purchase of the disputed Diaoyu Islands and appealed to both China and Japan to bring the territorial row to a peaceful resolution.
Niwa, who saw Sino-Japanese relations decline to their worst level in years before leaving the post last month, said the only option for both countries was to put aside their differences.
His criticism came as former Japanese prime minister Tomiichi Murayama arrived in China in the latest effort to use diplomatic backchannels to restore ties. Former prime minister Yukio Hatoyama also recently visited. Both senior leaders are considered friendly to China.
Niwa said he questioned the haste of then prime minister Yoshihiko Noda in deciding to buy the islands - known as the Senkakus in Japan - from the Japanese Kurihara family for about two billion yen (HK$170.6 million) in September.
"As ambassador I did ask why the Japanese government was in such a rush and took the decision to purchase the islands in a matter of two days," Niwa said. "It is possible they [the Japanese government] had information that will never come to light, but personally speaking, I don't think the timing of the decision was ideal."
It is widely believed that Noda's hand was forced by Shintaro Ishihara, who was then governor of Tokyo and had six months before announced his own plans to purchase the islands and administer them as a part of Tokyo.
A fund to carry out Ishihara's plan had managed to raise 314 million yen in a matter of weeks.
A number of analysts have suggested that if Ishihara, a well-known nationalist, had purchased the islands instead of the national government, hostilities with China may have broken out.
Niwa played down that suggestion: "Knowing what I do about the two nations and their people, I cannot think that would have happened.
"For Japan and China, there is only one road for us to take as we go forward and that is to follow the path of friendship."
He added: "Although we are in a very difficult situation at the moment, the appearance of the cherry blossoms here in Japan comes after the snow has melted.
"There are many things that affect relations between China and Japan, but I believe there will be an environment that is conducive to the ice melting in the near future."
It's unclear whether that optimism is shared by newly elected Japanese Prime Minister Shinzo Abe, whose envoy met Chinese Communist Party chief Xi Jinping in Beijing last week.
In his inaugural policy address to parliament yesterday, Abe steered clear of China and the disputed islands, but conceded that "the situation around Japan is increasingly severe".
"My cabinet will resolutely protect lives, assets and territory of Japan, both on the water and in the air, strengthening development and control, as well as security of remote islands on the border," he said without elaborating.
Additional reporting by Agence France-Presse, Associated Press