JAPAN has issued a strongly worded White Paper warning that China's potentially dangerous maritime activities could trigger unintended contingencies.
The defence White Paper, released yesterday, pointed to Chinese surveillance ships' frequent incursions into waters claimed by Japan around the disputed Senkaku islands - which the Chinese call Diaoyu - and also intrusions by Chinese jets into Japanese air space.
The two nations have been locked in a bitter territorial spat since Japan nationalised the rocky islands in the East China Sea last September.
The document also referred to a January incident in which, according to Japan, a Chinese navy frigate had locked its weapons radar on to a Japanese destroyer.
"We request that international rules be observed," it said.
Defence Minister Itsunori Onodera told reporters after the White Paper was endorsed by the Cabinet: "It is important to point out to international society the dangerous activities that invite unforeseen contingencies."
But he added that Tokyo is seeking a dialogue with Beijing "to build a mechanism for maritime communication between our two defence authorities".
Drawing attention as well to North Korea's nuclear and missile development programme, the White Paper described the security environment around Japan as growing "increasingly severe". Because of this, the presence of the United States military in the region is "still extremely important", it said.
The White Paper, released less than two weeks before nationwide Upper House elections on July 21, reminds the nation that Japan is far from solving longstanding territorial disputes that have marred its relations with China and also South Korea.
Incensed by the White Paper's reference to the disputed Takeshima islets as "Japanese territory", South Korea, which refers to them as Dokdo, demanded the immediate deletion of the reference.
There was no immediate reaction from Beijing. But Chinese surveillance vessels continued to be deployed around the disputed East China Sea islands yesterday.
Besides complaining about China's behaviour over the islands, the White Paper also expressed unhappiness at an article in the People's Daily in May that suggested Beijing has a valid claim to Japan's Okinawa island.
It also hit out at China's defence budget, saying it is far larger than Beijing cares to disclose, a view shared by the US.
This year's White Paper is marked by unprecedentedly strong language. The use of words such as "severe" and the many criticisms of China appear to reflect Prime Minister Shinzo Abe's tough stand on security issues. He has made no secret of his desire to revise the Constitution to allow Japan to exercise the right of collective self-defence.