During my two decades of work on China and Taiwan issues at the US State Department, I often admired Jerome A. Cohen's work.
He and Jon M. Van Dyke are entitled to their own opinions about the Senkaku Islands [known as the Diaoyus in China] - but, alas, not their own facts ('Lines of latitude', November 10).
Even Taiwan's President Ma Ying-jeou would reject their assertion that the islands 'have proved incapable of sustaining human habitation'.
As Mr Ma pointed out in his magisterial 1981 Harvard Law School thesis 'Legal Problems of Seabed Boundary Delimitation in the East China Sea' (p. 93), the main Senkaku Island, Uotsuri, possesses 'a [fresh water] spring big enough to accommodate 200 people'. He noted that in the early 1900s 'an enterprising Japanese named Koga brought scores of seasonal workers, food and supplies each year' to the island where he built 'houses, reservoirs, docks, warehouses and sewers'.
Mr Ma is hardly a cheerleader for Japan's title to the islands.
However, he acknowledged that Koga's son continued a fish processing operation on the island until the early 1940s when the settlement's population had grown to 248, according to Okinawa Prefecture household registry records.
Uotsuri was evacuated during the second world war, and the United States military, which occupied the islands of Okinawa Prefecture from 1945 until 1972, used the island for naval gunnery practice, all the while paying an annual rent for the privilege to the Koga clan.
In 1951, the US signed the San Francisco Peace Treaty - by constitutional definition, America's 'law of the land' - Article 3 of which placed under American trusteeship all islands south of 29 degrees north latitude, under Japanese administration at the end of the second world war, that were not otherwise specifically referred to in the treaty. And, under the treaty, the US government administered the Senkaku Islands as a part of the Ryukyu Islands. In 1970, the US State Department stated 'that residual sovereignty over the Ryukyus remains with Japan' and that the Senkakus were part of the Ryukyus.
Article 121 of the United Nations Convention on the Law of the Sea grants a 200-mile 'exclusive economic zone' delimitation to islands that can 'sustain human habitation or economic life of their own'.
There is no historical evidence that anyone but Japanese citizens ever inhabited and sustained economic activity in the Senkakus, so it is appropriate under international law for Japan to use the islands to delineate its current EEZ baselines.
To debate the ancient history of the Senkakus as a matter of Chinese territorial claims strikes me as pointless as debating equally ancient Chinese claims on Mongolia, North Korea, Vietnam and India. Surely, Professors Cohen and Van Dyke recognise this.
John J. Tkacik, Alexandria, Virginia, US