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.
Japan Coast Guard resources wearing thin due to Diaoyus dispute
The need to constantly monitor waters means other essential tasks are being neglected
Julian Ryall in Tokyo
The Japan Coast Guard is devoting so many resources to protecting the disputed Senkaku Islands that it could affect its other duties, including search and rescue operations for ships in distress.
Coastguard units in southern Japan have been at an elevated state of alert for the three weeks since the Japanese government announced last month that it was nationalising the disputed islands, called the Diaoyus by Chinese, by buying three of them from the family that claims to own them.
Beijing's ships arrived three days later and, at one point, there were as many as 13 mainland Chinese vessels in waters close to the disputed islands.
Coastguard vessels from Taiwan have also entered Japanese waters, along with dozens of fishing boats flying banners proclaiming that the islands are sovereign Taiwanese territory.
The need to constantly monitor the waters around the islands is taking its toll on the Japanese coastguard.
Although a spokesman for the service was unable to comment on its operations, senior officials were having to shuffle their resources.
It is noticeable, for example, that the regional headquarters of the JCG in Yokohama has very few vessels in port.
Normally, the unit has many as 10 of its 15-strong fleet alongside the harbour; but within the last few days only a single vessel remained.
"The coastguard is having to work with much more limited amounts of equipment," Masafumi Iida, an analyst with the National Institute of Defence Studies, told the Post.
"The service is charged not only with protecting the sovereignty of the Senkaku Islands, but also with search and rescue operations and a wide range of other tasks in waters all around the country," he said. "Of course, protecting Japanese sovereignty is the service's top priority, but that means that other responsibilities are being affected by Chinese activities around the islands."
Potentially, this could lead to search and rescue operations being delayed, he agreed. In some cases, delays could prove fatal, particularly as winter approaches.
The coastguard fleet numbers 121 vessels, with nine stationed in Naha, the main port of Okinawa prefecture and the closest base to the Senkaku Islands.
Reports says this force has been reinforced by 20 ships from other regions, all of which need constant refuelling and maintenance, and rest for the crews.
The Japan Coast Guard has a mere 12,600 personnel across the country and the crisis has stretched resources.