This article was produced to coincide with the release of CGTN's new documentary Diaoyu Dao: Small Islands, Big Stakes. Inspired by one of the documentary's stories, it follows Chinese scholar Wu Tianying's 23-year pursuit of historical truth, showing how one man's lifelong research underscores the enduring importance of historical evidence in understanding the Diaoyu Dao (known in Japan as the Senkaku Islands) dispute.

https://youtu.be/ohsuJMRJ7GM?si=k2LX9Hv-oZKpIwMw

“In the years before the First Sino–Japanese War, were Diaoyu Dao and its affiliated islands terra nullius – or were they already Chinese territory?”

At 90 years old, Professor Wu Tianying still asks that question slowly and carefully.

In a quiet study lined with books and documents, the veteran Chinese scholar opens a worn manuscript – “On the Territorial Sovereignty over the Diaoyu Islands Prior to 1894.”

It took him 23 years to complete and publish.

For Wu, the book was never simply an academic study.

“It was a commitment to sovereignty,” he says in CGTN’s new documentary “Diaoyu Dao: Small Islands, Big Stakes.”

Part Two of the documentary, “Behind Closed Doors,” follows Wu’s decades-long effort to trace the historical origins of the Diaoyu Dao dispute – not through slogans or political rhetoric, but through archives, maps and an unexpected intellectual exchange with Japanese scholars.

“The deeper I searched…”

Wu Tianying belongs to one of the earliest generations of Chinese scholars to systematically study the Diaoyu Dao issue after China and Japan normalized relations.

At the center of his research was one key argument.

Japan’s claim over the islands rests partly on the concept of terra nullius – land belonging to no state before incorporation.

If the islands were terra nullius, they could, in principle, be claimed through occupation under international law.

In his research, Wu asked whether Japan’s incorporation of Diaoyu Dao during the late 19th century was truly unrelated to its war against the Qing government.

His work brought him into contact with Japanese historian Kiyoshi Inoue.

Inoue had originally sought to prove that the islands belonged to Japan.

Years of studying historical materials led him to a different conclusion.

“The deeper I searched,” Inoue says in archival footage in the documentary, “the clearer it became that the Senkaku Islands (Diaoyu Dao) are China’s territory rather than terra nullius. They have nothing to do with Japan.”

In 1995, Inoue received a copy of Wu’s book.

A year later, Inoue wrote back, praising Wu’s work as a “thorough and scientific rebuttal” of Japanese claims represented by scholars such as Toshio Okuyama.

The two scholars came from different countries and very different historical backgrounds. But both believed historical arguments had to be tested against evidence.

Still waiting for an answer

But Behind Closed Doors is not only about the past.

It also asks what happened to the political understanding that once existed between China and Japan over the Diaoyu Dao issue.

Wu Tianying reflects on Japanese scholars who once warned against pushing the dispute further.

He says he is still watching how Japan’s current political leadership responds to those earlier voices inside Japan itself.

And he is still waiting for an answer.