The central government deported 14 Chinese activists just two days after seven of them landed on the disputed islands, apparently to prevent Japan-China relations from deteriorating even further.
The decision sparked criticism of Japan's stance toward China as weak.
However, after its relations with South Korea became strained recently over the Takeshima islands, the government decided it must avoid a two-pronged fight with its Asian neighbours.
The 14 activists, including members of a private anti-Japan group based in Hong Kong, were deported Friday, two days after seven of them illegally landed on Uotsurijima island in Ishigaki, Okinawa Prefecture, on Wednesday.
From the outset, the government has responded cautiously to this incident.
Chief Cabinet Secretary Osamu Fujimura justified the government's stance at a press conference held Friday. "Instead of making emotional judgments, we have responded to this matter strictly and fairly based on our domestic laws," Fujimura said.
However, Tokyo Gov. Shintaro Ishihara denounced the government's decision. "I have witnessed, once again, the weak-kneed diplomacy of the central government against China--or rather, the government's pitiful attitude of pandering to China's interests," he said at a press conference the same day.
Ishihara, who is known for his hard-line stance toward China, pointed out that the activists hurled bricks at the Japan Coast Guard's patrol vessel. "Isn't this an obstruction of justice? A nation incapable of enforcing its laws is not a nation," Ishihara said.
Shigeru Ishiba, the Liberal Democratic Party's chairman of its special committee on territories, also criticised the government on a TV Asahi programme on Friday. "The government failed to apply the law properly," he said.
Article 65 of the Immigration Control and Refugee Recognition Law stipulates that authorities can directly transfer suspects arrested on suspicion of violating the law to the Immigration Bureau, but only if there are no other charges.
The government applied this article to the activists and refrained from sending them to the Naha District Public Prosecutors Office, giving up further investigation into the case.
Ishihara and Ishiba questioned whether it was appropriate for the government to apply Article 65 to this case.