WASHINGTON — These were cold calculations, at the outset of what came to be called the Cold War:
Could radioactive poisons be fashioned into a weapon to assassinate civilian or political leaders?
Could the highly toxic materials be inconspicuously dispersed in a room — perhaps in aerosol form — to kill “important individuals”?
Could the deed be done covertly, leaving behind no hint of U.S. government involvement?
These questions marked the starting point for a long-secret project approved at the highest levels of the Army in 1948 — not to decide when, or even if, to use such a weapon but to determine whether it was even feasible. This was just three years after the first atomic bombs were detonated — in a test in the New Mexico desert in July 1945 and then twice in Japan to end World War II.
It was the atomic bomb project itself that made U.S. scientists realize the potential for radiological warfare.
It has been known for years that the U.S. military pursued radiological warfare concepts, but newly declassified documents obtained by The Associated Press provide what military historians said appear to be the first indication that the work included exploring the potential for using radioactive poisons as an assassination weapon.
Targeting public figures in such attacks is not unheard of; just last year an unknown assailant used a tiny amount of radioactive polonium-210 to kill Kremlin critic and former KGB agent Alexander Litvinenko in London.
No targeted individuals are mentioned in references to the assassination weapon in the government documents declassified in response to a Freedom of Information Act request filed by the AP in 1995.
The decades-old records were released recently to the AP, heavily censored by the government to remove specifics about radiological warfare agents and other details. The censorship reflects concern that the potential for using radioactive poisons as a weapon is more than a historic footnote; it is believed to be sought by present-day terrorists bent on attacking U.S. targets.
The documents give no indication whether a radiological weapon for targeting high-ranking individuals was ever used or even developed by the United States. They leave unclear how far the Army project went. One memo from December 1948 outlined the project and another memo that month indicated it was under way. The main sections of several subsequent progress reports in 1949 were removed by censors before release to the AP.