US Considered Radiological Weapon

In one of the longest-held secrets of the Cold War, the U.S. Army explored the potential for using radioactive poisons to assassinate "important individuals" such as military or civilian leaders, according to newly declassified documents obtained by The Associated Press.

Approved at the highest levels of the Army in 1948, the effort was a well-hidden part of the military's pursuit of a "new concept of warfare" using radioactive materials from atomic bombmaking to contaminate swaths of enemy land or to target military bases, factories or troop formations.