In 1967, Foreign Minister Takeo Miki expressed his interest in the peaceful use of "nuclear explosion energy" in a meeting with his U.S. counterpart, but the U.S. side reacted cautiously, according to a diplomatic document declassified Tuesday.
The use of nuclear explosives for civil engineering work, among other purposes, could result in widespread atomic fallout and proliferation.
According to newly declassified minutes of the meeting of Sept. 16, 1967, with U.S. Secretary of State Dean Rusk, Miki urged countries with nuclear weapons to express their determination to pursue disarmament on the grounds that Japan was "abandoning forever" its capacity to develop nuclear weapons.
If nuclear explosion energy became available as an option, Miki, who was foreign minister in the Cabinet of Prime Minister Eisaku Sato, said, "We would like to have an equal chance to use it."
Rusk countered that the nuclear explosion required to destroy a mountain in civil engineering work would also be capable of destroying a city.