Declassified files reveal US nuclear drills in Japan during cold war

Declassified American military records indicate that US forces based in Japan actively prepared for the possibility of nuclear warfare during the height of the Cold War. According to a report by Japan's Kyodo news agency, troops carried out several simulated hydrogen bomb exercises in the early 1970s, likely envisioning scenarios involving the Soviet Union or China.

Drills in Okinawa Before and After Reversion

The analysis, conducted jointly with researcher Takuma Nakashima, examined declassified "Command Chronology" files from a US command center in Iwakuni, Yamaguchi prefecture, covering 1970 to 1974. The documents show that US Air Force personnel from Iwakuni participated in these nuclear readiness drills in Okinawa prefecture between at least 1971 and 1975. Notably, these exercises occurred both during and after the US occupation of Okinawa, which lasted from 1945 until the islands' return to Japanese control in May 1972.

Lasting US Military Presence in Japan

The revelations shed new light on the extensive wartime preparations undertaken by US forces in Japan, Washington's key ally in the Asia-Pacific region. Today, Japan continues to host a substantial US military presence, including more than 50,000 troops, numerous bases, and advanced weapons systems, underscoring the enduring strategic partnership that originated in the post-World War II and Cold War eras. The newly public documents provide a historical context for this ongoing security arrangement.