Signals intelligence showed Soviet 4th Air Army alert “included preparations for immediate use of nuclear weapons” in response to NATO exercise
Key “End of Tour Report Addendum" by Lt. Gen. Leonard Perroots who oversaw Able Archer 83, subject of National Security Archive lawsuit, declassified by State Department Historian’s Office
Perroots described “ominous picture” of War Scare, the Soviet alert, and his decision not to escalate
CIA response admitted intelligence failures and possibility of “serious escalatory consequences”