Washington, D.C., August 31, 2026 - The “fundamental reevaluation” that took place in the Kremlin under General Secretary Mikhail Gorbachev not only encompassed the political, ideological, and economic spheres but also included fundamental changes in military doctrine, according to declassified U.S.
Washington, D.C., November 14, 2025 - The State Department quietly deleted important archival records from an official history detailing how a 1983 NATO war game could have led to a catastrophic nuclear exchange, according to new reporting from the Washington Post. This is the first known instance in which the State Department has removed previously declassified and published documents from one of its Foreign Relations of the United States (FRUS) volumes, according to the report.
Washington, D.C., October 15, 2025 - The 1968 crash of a nuclear-armed B-52 bomber near the U.S. Air Force Base in Thule, Greenland, that scattered radioactive plutonium across miles of icefields created an environmental catastrophe that demanded a quick response and a political crisis for the Danish government that exposed contradictions in its no-nuclear policy.
Washington, D.C., September 25, 2025 - Newly published documents and photographs concerning the radiation and blast effects of the August 1945 bombings of Hiroshima and Nagasaki provide graphic details on how U.S. and British officials first assessed the deadly impact of the atomic weapons. These and other records published today are among the data and evidence that helped undermine the public claim made at the time by Manhattan Project director Gen. Leslie Groves that radiation sickness was “a pleasant way to die.”
The first full U.S. report on the results of the atomic bombing of Hiroshima, 80 years ago this week, made a “conservative estimate” that around 100,000 people had been killed, according to a newly published report from the U.S. Army Air Forces on Tinian Island, dated August 8, 1945.
Washington, D.C., July 16, 2025 - Early in the morning of 16 July 1945, 80 years ago, the U.S. Manhattan Project staged the first test of a nuclear weapon in the New Mexican desert. It was the first trial of a plutonium implosion weapon—the same weapon type that devastated Nagasaki a few weeks later. The explosion on the ground produced radioactive fallout contaminating over 1,100 square miles of the state, with some debris spreading as far north as Canada.
Washington, D.C., June 3, 2025 - The Trump administration’s intention to acquire Greenland, including possibly by force, has put a focus on the history of its strategic interest to U.S. policymakers. Today, the National Security Archive publishes the first of a two-part declassified document collection on the U.S. role in Greenland during the middle years of the Cold War, covering the decisions that led to the secret deployment of U.S.
Washington, D.C., December 17, 2024 - A recently declassified Joint Atomic Energy Intelligence Committee (JAEIC) report from December 1960 is the first and only known U.S. intelligence report to correctly and unequivocally state that Israel’s Dimona nuclear project would include a reprocessing plant for plutonium production and was weapons related. All known, subsequent U.S. intelligence products treated the reprocessing issue as unsettled until the late 1960s, when Israel reached the threshold of a nuclear weapons capability and the U.S.
Washington, D.C., August 8, 2024 – On the week of the 79th commemoration of the U.S. atomic bombings of Hiroshima and Nagasaki, Japan, the National Security Archive today publishes a fascinating new collection of papers from the office files of Leslie Groves, the director of the Manhattan Project, the U.S. effort during World War II to develop and produce the world’s first nuclear weapons.