Kyodo News | Masakatsu Ota | Tokyo, Jan. 23, 2015
Top U.S. military officials considered giving the Japanese Self-Defense Forces atomic weapons in the 1950s under an arrangement similar to NATO’s “nuclear-sharing” deal, declassified U.S. Joint Chiefs of Staff documents revealed on Friday.
In February 1958, the Joint Chiefs of Staff decided its “position,” saying “The United States would prefer that Japan integrate appropriate atomic weapons into the Japanese self-defense forces.” The decision came five months after the U.S. military and the SDF conducted a joint map exercise assuming use of nuclear weapons, according to the JCS documents.
The nuclear map exercise, conducted in September 1957, had never been revealed to the public until a joint investigation by Kyodo News and Akira Kurosaki, associate professor of Fukushima University, uncovered the documents recently at the U.S. National Archives in Maryland.
As Cold War tensions rose in the 1950s with the Soviet Union’s successful nuclear tests and its development of hydrogen bombs, the administration of President Dwight Eisenhower dramatically increased its dependence on nuclear arms under its “New Look” policy that equated them with conventional weaponry.
The JCS decision on a potential nuclear option for Japan, which had come under nuclear attack the previous decade, suggests the U.S. Cold War mentality relied on nuclear arsenals as a countermeasure against the massive conventional capability of the Soviet bloc.
A JCS document dated Feb. 17, 1958 said “a combined U.S.-Japan Map Exercise FUJI was conducted in Japan during the period 24-28 September 1957,” in which the use of nuclear weapons was simulated.
The document does not mention the specific venue of the exercise. But an oral record left by late former senior Ground Self-Defense Force official, Gen. Ryuhei Nakamura at National Institute of Defense Studies, a research branch of Japan’s Defense Ministry, indicated that “FUJI” was held at the U.S. Camp Drake located in areas straddling Tokyo and Saitama Prefecture.
According to this oral record, the Japanese participants wanted to know how the U.S. military would use tactical nuclear weapons in Japan. However, the U.S. side did not provide precise information.
Still, the JCS documents detailed questions raised by the Japanese “Co-Director” during the joint map exercise.
“Would the United States hold all the nuclear weapons for use by her own delivery systems or would the United States release some weapons for use by Japan?” the JCS document paraphrased the questions posed by the Co-Director.
He also presented other questions such as; “Would the United States prefer Japan to have conventional weapons only?” “If Japan were to decide to arm herself with nuclear weapons, could she depend upon U.S. support for such a plan?”
A memorandum by the Chief of Naval Operations, Adm. Arleigh Burke, dated Nov. 20, 1957, said “the significance of the questions posed by the Japanese Co-Director…warrants the early consideration of the Joint Chiefs of Staff.” “These questions express the concern of the only country in the world that ever experienced a nuclear attack…” the memorandum added.
In response to Burke’s suggestion, the Joint Chief of Staff finally decided its positions at a meeting on Feb. 12, 1958.
The JCS document dated Feb. 17, 1958 elaborates its positions, saying “(t)he provision of such weapons support to Japan would be primarily dependent on the desires of Japan to be provided with atomic weapons and her development of capability to employ effectively such weapons.”
In addition to U.S. preference for integration of atomic weapons with the SDF, the JCS document said, “(the SDF) must eventually be equipped with the most modern conventional and atomic weapons.” These JCS positions were conveyed to CINCPAC, Commander in Chief Pacific Command.
Another JCS document dated Sept. 17, 1958, noted “(t)he United States is willing to support her allies with atomic weapons, after the NATO pattern, subject to the desire of Japan to acquire such weapons and to develop a capability for their effective employment.”
Such JCS positions on arming the SDF with nuclear weapons were not formally proposed to the Japanese government.
Other declassified U.S. documents obtained by Kyodo News suggested caution by U.S. policymakers who were familiar with Japan’s volatile domestic situation and growing antinuclear sentiment following the Lucky Dragon incident in March 1954, when Japanese fishery vessels were exposed to radiation fallout from the U.S. thermo-nuclear “Bravo Shot” near Bikini Atoll in the Pacific.
“The U.S. military considered integration of nuclear weapons into the SDF and some SDF officials showed interest in this idea,” Kurosaki said.
“There was a backdrop that the U.S. administration deepened its dependence on nuclear weapons in its national security strategy. From these contexts, then Prime Minister (Nobusuke) Kishi stated it is possible for Japan to possess nuclear weapons (for defensive purpose) even under the Constitution,” he said.
Kurosaki said he wonders if Japan would have continued to be a nonnuclear power if the Lucky Dragon incident had not taken place and antinuclear sentiment in Japan had not risen so sharply.
On the Japanese side, from mid-1950s to mid-1960s, the Staff College of the Japanese GSDF taught future top officials about nuclear tactics and doctrines which were imported from the U.S. Command and General Staff College (CGSC), former SDF top officials told Kyodo News recently.
“Which direction would nuclear fallouts move and how should we conduct military operation evading these fallouts? These were brought back to Japan by SDF official who studied (nuclear tactics) at the U.S. CGSC,” former GSDF Major Gen. Kiyoshi Maekawa said.
But, the nuclear tactical education at the Staff College in Tokyo was suspended later in 1960s due to growing antinuclear public sentiment and governmental policies culminated in the three nonnuclear principles, which were introduced by Prime Minister Eisaku Sato in 1967.
“The Lucky Dragon Incident, the (national-level) ban-the-nuclear bomb movement and three nonnuclear principles created a lot of impact” on SDF’s position, former GSDF Gen. Mitsuaki Yokochi said.