United States nuclear weapons were stored secretly at bases throughout Japan following World War II. Secret agreements between the two governments allowed nuclear weapons to remain in Japan until 1972, to move through Japanese territory, and for the return of the weapons in time of emergency.

Nuclear war planning

In the 1950s, after U.S. interservice rivalry culminated in the Revolt of the Admirals, a stop-gap method of naval deployment of nuclear weapons was developed using the Lockheed P-2 Neptune and North American AJ-2 Savage aboard aircraft carriers. Forrestal-class aircraft carriers with jet bombers, as well as missiles with miniaturized nuclear weapons, soon entered service, and regular transits of U.S. nuclear weapons through Japan began thereafter.

U.S. leaders contemplated a nuclear first strike, including the use of those based in Japan, following the intervention by the People's Republic of China during the Korean War. A command-and-control team was then established in Tokyo by Strategic Air Command and President Truman authorized the transfer to Okinawa of atomic-capable B-29s armed with Mark 4 nuclear bombs and nine fissile cores into the custody of the U.S. Air Force.

The runways at Kadena were upgraded for Convair B-36 Peacemaker use.Gibraltar of the Pacific. (March 10, 1952) The Pittsburgh Press, Pittsburgh, Pennsylvania. Page 15. Reconnaissance RB-36s were deployed to Yokota Air Base in late 1952.Hall, R. Cargill. "The Truth About Overflights: Military Reconnaissance Missions over Russia Before the U-2." Quarterly Journal of Military History, Spring 1997. Boeing B-50 Superfortress and Convair B-36 Peacemaker bombers were deployed to Japan and Okinawa in August 1953 to join B-29s already based there.

Following the Korean War, U.S. nuclear weapons based in the region were considered for Operation Vulture to support French military forces in Vietnam.

By the 1960s Okinawa was known as "The Keystone of the Pacific" to U.S. strategists and as "The Rock" to U.S. servicemen. Okinawa was critical to America's Vietnam war effort where commanders reasoned that, "without Okinawa, we cannot carry on the Vietnam war." During U.S. involvement in the Vietnam War the use of nuclear weapons was suggested in order to "defoliate forests, destroy bridges, roads, and railroad lines." In addition, the use of nuclear weapons was suggested during the planning for the bombing of Vietnam's dikes in order to flood rice paddies, disrupt the North Vietnamese food supply, and leverage Hanoi during negotiations. Each of the cold war plans employing a U.S. launched nuclear first strike were ultimately rejected.

Strategic Air Command had designated Kadena (as well as Yokota Air Base on the mainland), as a dispersal location for new airborne command post aircraft, codenamed "Blue Eagle", in 1965. The 9th Airborne Command and Control Squadron of the 15th Air Base Wing provided this airborne command and control to Commander in Chief Pacific Command from Hickam Air Force Base, Hawaii, after 1969. and Specially-equipped United States Navy C-130s, operating from Japanese bases, enabled the National Command Authority to control Single Integrated Operational Plan (SIOP) processes for theater or general nuclear war. These exercises continued at least into the 1990s.

Nuclear weapons deployment, storage and transit Okinawa hosted 'hundreds of nuclear warheads and a large arsenal of chemical munitions,' for many years.

Article 9 of the Japanese Constitution, written by the GHQ six months after the war, contains a total rejection of nuclear weapons. But when the U.S. military occupation of Japan ended in 1951, a new security treaty was signed that granted the United States rights to base its "land, sea, and air forces in and about Japan."

In 1959, Prime Minister Nobusuke Kishi stated that Japan would neither develop nuclear weapons nor permit them on its territory". He instituted the Three Non-Nuclear Principles--"no production, no possession, and no introduction."

A 1960 accord with Japan permits the United States to move weapons of mass destruction through Japanese territory and allows American warships and submarines to carry nuclear weapons into Japan's ports and American aircraft to bring them in during landings. The agreement allows the United States to deploy or store nuclear arms in Japan without requiring the express permission of the Japanese Government. The discussion took place during negotiations in 1959, and the agreement was made in 1960 by Aiichiro Fujiyama, then Japan's Foreign Minister.

There were many things left unsaid; it was a very sophisticated negotiation. The Japanese are masters at understood and unspoken communication in which one is asked to draw inferences from what may not be articulated.

The secret agreement was concluded without any Japanese text so that it could be plausibly denied in Japan. Since only the American officials recorded the oral agreement, not having the agreement recorded in Japanese allowed Japan's leaders to deny its existence without fear that someone would leak a document to prove them wrong. The arrangement also made it appear that the United States alone was responsible for the transit of nuclear munitions through Japan. However, the original agreement document turned up in 1969 during preparation for an updated agreement, when a memorandum was written by a group of U.S. officials from the National Security Council Staff; the Departments of State, Defense, Army, Commerce and Treasury; the Joint Chiefs of Staff; the Central Intelligence Agency; and the United States Information Agency.

A 1963 national intelligence estimate authored by the Central Intelligence Agency, Japans Problems and Prospects stated that:

Post-war governance of Southern Japanese Island chains

After the Battle of Okinawa the island was first placed under the control of the United States Navy. Following the surrender of Japan, the U.S military occupied Japan and Okinawa was put under control of the United States Military Government of the Ryukyu Islands on September 21, 1945, and an Okinawa Advisory Council was created. Following the war, the Bonin Islands including Chichi Jima, the Ryukyu Islands including Okinawa, and the Volcano Islands including Iwo Jima were retained under American control.

In 1952 Japan signed the Treaty of San Francisco that allowed the future control of Okinawa and Japan's southern islands by the United States Military Government (USMG) in post-occupation Japan. The United States Civil Administration of the Ryukyu Islands (USCAR), as part of the Department of Defense, maintained overriding authority over the Japanese Government of the Ryukyu Islands.

Return The Johnson administration gradually realized that it would be forced to return Chichi Jima and Iwo Jima "to delay reversion of the more important Okinawa bases" however, President Johnson also wanted Japan's support for U.S. military operations in Southeast Asia." Prime Minister Eisaku Satō and Foreign Minister Takeo Miki had explained to the Japanese parliament that "the return of the Bonins had nothing to do with nuclear weapons yet the final agreement included a secret annex, and its exact wording remained classified." A December 30, 1968, cable from the U.S. embassy in Tokyo is titled "Bonin Agreement Nuclear Storage," but within the same file "the National Archives contains a 'withdrawal sheet' for an attached Tokyo cable dated April 10, 1968, titled 'Bonins Agreement--Secret Annex,'". The Bonin and Volcano islands were eventually returned to Japan in June 1968. On the one-year anniversary of a B-52 explosion and near-miss at Kadena Prime Minister Sato and President Nixon met in Washington, DC where several agreements including a revised Status of Forces Agreement (SOFA) and a formal policy related to the future deployment of nuclear weapons on Okinawa were reached.

A draft of the November 21, 1969, Agreed Minute to Joint Communique of United States President Nixon and Japanese Prime Minister Sato was found in 1994. The English text of the draft agreement reads:

United States President:

Japanese Prime Minister:

Nuclear weapons bases in Japan

A declassified 1956-57 Far East Command manual, Standing Operating Procedures for Atomic Operations, revealed that, there were thirteen locations in Japan that "had "nuclear weapons or their components, or were earmarked to receive them in times of crisis or war." Among the nuclear-capable base locations were Misawa Air Base and Itazuke Air Bases and Yokosuka and Sasebo on U.S. Navy warships that held nuclear weapons. The Bulletin of the Atomic Scientists reveals that the other locations that held nuclear weapons in Japan were Johnson Air Base, Atsugi Air Base, Komaki Air Base, and Iwakuni Air Base.

Southern Japanese Island chains The island chains were among the thirteen separate locations in Japan that had nuclear weapons. According to a former U.S. Air Force officer stationed on Iwo Jima, the island would have served as a recovery facility for bombers after they had dropped their bombs in the Soviet Union or China. War planners reasoned that bombers could return Iwo Jima, "where they would be refueled, reloaded, and readied to deliver a second salvo as an assumption was that the major U.S. Bases in Japan and the Pacific theater would be destroyed in a nuclear war." It was believed by war planners that a small base might evade destruction and be a safe harbor for surviving submarines to reload. Supplies to re-equip submarines as well as anti-submarine weapons were stored within caves on Chichi Jima.

Okinawa

At one point Okinawa hosted approximately 1,200 nuclear warheads. The Okinawa-based nuclear weapons included 19 different weapons systems.

From 1955–56 to 1960, the 663rd Field Artillery Battalion operated the Army's 280mm M65 Atomic Cannon ("Atomic Annie") from Okinawa. In the 1960s, nuclear storage locations included four MGM-13 Mace missile sites, Chibana at Kadena Air Base, Naha Air Base, Henoko [Camp Henoko (Ordnance Ammunition Depot) at Camp Schwab], and the Army MIM-14 Nike-Hercules air defense launch locations.

Nuclear Weapons in Okinawa WeaponPeriodDate of withdrawalNonnuclear bomb Jul 54 Jun 67Bomb Dec 54-Feb 55 Jun 72M65 280mm gun Dec 55-Feb 56 Jun 608-inch howitzer Jun-Aug 57 Jun 72MGM-1 Matador Sep-Nov 57 Dec 60Nuclear depth bomb Dec 57-Feb 58 Jun 72Special Atomic Demolition Munition Feb-May 58 Jun 72MGR-1 Honest John Dec 57-Feb 58 Jun 72MIM-14 Nike Hercules Jan-Mar 59 Jun 72MGM-5 Corporal Mar 60 Jun 65Mk 105 Hotpoint bomb Jul-Sep 60 Dec 60MGM-18 Lacrosse Oct-Dec 60 Dec 63MGM-13 Mace Apr-Jun 61 Jun 70AIM-26 Falcon Jul-Sep 61 Jun 72MGR-3 Little John Apr-Jun 62 Dec 68ASROC Jan-Mar 63 Apr 66RIM-2 Terrier Jan-Mar 64 Jun 64Davy Crockett Apr-Jun 64 Dec 68155mm howitzer May 66 Jun 72

From 1961 to 1969, the 498th Tactical Missile Group operated the MGM-13 Mace nuclear-armed cruise missile on Okinawa. Thirty-two Mace missiles were kept on constant alert in hardened hangars at four Okinawa launch sites by the 873d Tactical Missile Squadron. and The four Mace sites were assigned to Kadena Air Base and located at Bolo Point in Yomitan, Onna Point, White Beach, and in Kin just north of Camp Hansen.

There were eight Nike-Hercules launch sites dispersed throughout the Ryukyu Islands. The Integrated Fire Control area (IFC) for the islands anti-air missile systems was located at Naha AFB. The Army's 97th Anti-Aircraft Artillery Group received Nike-Hercules SAMs in 1959, and with two name changes (the formation became the 30th Artillery Brigade (Air Defense) and then the 30th Air Defense Artillery Brigade), the U.S. Army continued to operate the Nike missiles there until June 1973, when all the Nike sites were turned over to the Japan Air Self-Defense Force.

North American F-100 Super Sabre fighter-bombers capable of carrying hydrogen bombs were also present at Kadena Air Base.