In 1969, then Foreign Minister Kiichi Aichi told the Soviet Union that Japan was capable of arming itself with nuclear weapons but stressed that its people were strongly resolved not to do so, according to diplomatic documents declassified Thursday by the Foreign Ministry.
Aichi made the remark during a meeting with Soviet Premier Aleksei Kosygin at the Kremlin on Sept. 4, 1969, in a bid to fend off pressure from the Soviet Union to join the Nuclear Nonproliferation Treaty, which would come into force the following year.
Japan at the time was hesitant to sign the treaty amid worries that such a move might hamper its peaceful use of nuclear power.
During the meeting, Kosygin declared the Soviet Union's decision to ratify the treaty and urged Japan to follow suit, saying, "It's not understandable that the only nation that experienced atomic bombings is unwilling to sign the treaty."
Aichi held off on making a decision on the signing and said, "Japan is capable of arming itself with nuclear weapons if it intends to do so, yet it has sworn not to become a nuclear power by any means."