A U.N. survey in the 1970s that said oil and gas may lie beneath the surrounding waters changed that. Then, the Law of the Sea Convention introduced the idea of 200-nautical-mile exclusive economic zones, or EEZs, which give coastal countries sole exploitation rights over all natural resources contained within.
China's new baselines are a prelude to defining that exclusive zone. It has drawn straight lines around the main group of islands and a separate set around isolated Chiwei Island, some 50 nautical miles to the east.
It also plans to submit a document outlining the outer limits of its sea bed — those that stretch beyond 200 nautical miles from land — in the East China Sea to a U.N. commission. The move is a way for China to underscore its claim, but has little real impact. The commission, which comprises geological experts, evaluates the markers on technical grounds but has no authority to resolve overlapping claims.
"That puts a line in the sand, but it doesn't have any legal impact," said Ian Townsend Gault, director of the Centre for Asian Legal Studies at the University of British Columbia in Canada.
He doubts whether the islands would be capable of generating a 200-nautical-mile EEZ because they are too insignificant — too small and without a population.
"They are not important in the economic sense, no matter how beautiful they look on postcards," he said.
Legal questions aside, China sees the waters within its baselines as its internal waters under Beijing's administration.
That raises the risk of a confrontation in the clear waters around the disputed islands between Japanese coast guard vessels and Chinese fishing boats and law enforcement vessels, and even Taiwanese vessels — all ostensibly with orders to patrol the area.
Already there has been sparring the past two weeks, with Chinese maritime surveillance vessels entering waters Japan claims, and the Japanese coast guard firing a water cannon at Taiwanese boats approaching the islands.
The parties could legally resolve their dispute if they submit it to the International Court of Justice in The Hague, the International Tribunal for the Law of the Sea in Hamburg, Germany, or their own court.
"Both would be equally terrified of losing on flimsy grounds," said Townsend Gault. "They have snookered each other legally and diplomatically speaking. They have driven each other into a corner. We need some third party to say can you put this to bed so we don't have this enormous disruption in your bilateral relations whereby people are smashing up Toyota dealerships."
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