Former Prime Minister Nobusuke Kishi set a two-year timeline to revise the postwar security treaty with the United States as a precursor to an amendment of the pacifist Constitution, according to diplomatic records declassified Wednesday.

Kishi, an archconservative and Prime Minister Shinzo Abe’s grandfather, was preparing for his first visit to the United States as leader in 1957 when he started putting his plan into action.

Kishi’s idea was to seek a revision to the security treaty which, at the time, was widely seen across the political spectrum as putting the country in a subservient position.

He apparently believed that putting his ultimate focus on constitutional reform would push Washington to renegotiate the pact, giving Tokyo the chance to deepen defense cooperation with the U.S. through a revision of the supreme law.

The diplomatic records give a glimpse into Kishi’s strategy.

Kishi was known to be eager to revise the war-renouncing Constitution, which has remained unchanged since taking effect in 1947.

Abe is now looking to finish what his grandfather started with his quest to make a maiden constitutional amendment while bolstering the security alliance with the United States.

Kishi, who served as prime minister between 1957 and 1960, took issue with the United States security treaty and its Occupation of Ogasawara and other islands after Japan’s surrender in World War II.

The records show Kishi’s plan was incorporated in a confidential document created before his visit to the United States in June 1957 and its rough content was shared with U.S. Ambassador to Japan Douglas MacArthur, a nephew of the famous American general by the same name, who held a series of meetings with the prime minister before his trip.

A declassified document titled “the determination of the Japanese government regarding Japan-U.S. cooperation” states that bilateral relations “are not in an appropriate state for their further strengthening and development.”

Referring to elections in both houses of the Diet, later held in 1958 and 1959, respectively, Kishi said in the document he hoped to revise the security treaty and settle other issues before going to the polls.

“Under such circumstances, the two-thirds majority can be secured in both houses of the Diet (necessary to initiate an amendment) and a specific schedule can be set for a revision to the Constitution,” the document said. The proposal would then have needed to be approved by a majority of voters in a national referendum, as is still the case.

Since the war Japan has relied heavily on its defense alliance with the United States. However, the initial 1951 security treaty allowed U.S. troops to be stationed in the country but did not oblige them to come to its defense.

The diplomatic records also reveal the government weighed a push for the constitutional amendment five years after finalizing the envisaged revision of the security treaty, enabling the Self-Defense Forces to be dispatched overseas.

The government at the time brainstormed how to prepare for the potential conclusion of a mutual defense treaty with the United States.

Before Kishi traveled to the United States in June 1957, a total of nine meetings were held with MacArthur.

Kishi’s vision was conveyed to MacArthur during the seventh meeting on May 11 but was met with a negative response from the U.S. ambassador during the next meeting on May 15. The idea was reported to Washington in late May, the diplomatic records showed.

After meeting Kishi, U.S. President Dwight Eisenhower reaffirmed the American stance that Japan had residual sovereignty over the Ogasawara and Okinawa islands in a joint statement.

Japan and the United States also agreed to establish an intergovernmental panel to look into issues related to the security treaty. Negotiations toward revising the treaty began in October 1958.

Japan and the United States revised the security treaty in January 1960, but Kishi failed in his bid to amend the Constitution and conclude a mutual defense treaty.

Control of the Ogasawara islands and Okinawa reverted to Japan in 1968 and 1972, respectively.