This is the forth installment of a series.

Chinese Foreign Minister Wang Yi is known as being well-informed about Japan, as he is fluent in Japanese and has served as Chinese ambassador to Japan. Such a person is now sending a message to the international community that Japan and China agreed in the past to "shelve" the territorial issue over the Senkaku Islands.

On Sept. 20, Wang told the audience during a lecture at a think tank in Washington: "Forty-one years ago, when China and Japan achieved the normalization of diplomatic relations, leaders of the two nations reached a very important agreement...that is...we can set aside our difference [on the Senkaku issue] and take care of it or resolve it at some later date."

What does China's "shelving" agreement claim mean?

To understand what Wang intended to say, one must look back at how the issue unfolded.

The Senkaku Islands were included in Japan's territories in January 1895, after the nation confirmed the islands were not under the control of China, or Qing, at that time. The confirmation came after Japan conducted research over a decade or so.

Following Japan's defeat in World War II, the nation lost its overseas territories in line with the 1951 San Francisco Peace Treaty. However, 48 nations, including the United States-which signed the treaty-considered the Senkaku Islands as part of Okinawa and put them under US administrative control.

Under the Okinawa Reversion Agreement signed on June 17, 1971, the islands were returned to Japan.

However, after a UN research team brought up the possibility of oil reserves being located near the Senkaku Islands in 1969, China and Taiwan began to assert territorial rights over the islands in 1971 for the first time.

Under such a delicate situation, Japan and China formally established diplomatic relations in 1972.

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China claims Japan agreed to 'shelving' disputed islands issue