Japan pursued a de facto "two-China" policy recognizing both China and Taiwan while officially maintaining a one-China policy, according to declassified diplomatic documents released Wednesday.
A December 1964 document quotes Prime Minister Eisaku Sato as conveying this position to British Ambassador Francis Rundall.
"The Japanese government has been saying that there is only 'one China,' but we are simply using the words employed by both communist China and Nationalist China," the prime minister said. "In reality, we are aware that there are two governments."
That May, Foreign Minister Masayoshi Ohira told his British counterpart, Richard Butler, that Japan wanted to create a situation in which Taiwan could keep its U.N. seat even after China joined the world body.
"But communist China and Nationalist China are insisting on the idea that there is only one China," Ohira said.
The British foreign secretary responded by saying Britain was also convinced that Taiwan should remain a separate entity from communist China, although he wanted this view to be kept secret.
Butler insisted that to do so, it would be necessary for the Nationalist government in Taiwan to abandon the idea that it was the true ruler of all China. Britain recognized China in 1950.
Ohira, who later became prime minister, said Japan, in the final analysis, agreed with that view, but it would be premature to announce it as government policy.
Japan in 1952 signed a peace treaty with the Nationalist government, which fled to Taiwan in 1949. In 1972, Japan recognized Beijing and severed ties with Taipei.