More ominously, U.S. and NATO officers practiced the procedures they would have to follow to authorize and conduct nuclear strikes in an unpublicized exercise called Able Archer 83, shifting their headquarters as the game escalated toward chemical and nuclear warfare. In communications, they several times referred to non-nuclear B-52 sorties as nuclear "strikes" -- slips of the tongue that could have been intercepted by Soviet eavesdroppers.

While historians have previously noted the high risk of an accidental nuclear war during this period, the new documents make even clearer how the world's rival superpowers found themselves blindly edging toward the brink of nuclear war through suspicion, belligerent posturing and blind miscalculation.

In a coincidence that could have proved catastrophic, the script for the maneuvers dovetailed snugly and perilously with the Soviets' fears that they were under threat, coupled with nagging doubts about their ability to protect themselves from U.S. military might.

The problem with this brinksmanship was that it increased the risk of a nuclear exchange due to miscalculation, according to Nate Jones, a Cold War historian with the National Security Archive who edited and published the collection of more than 50 documents, totaling more than 1,000 pages, in three installments beginning May 16 and ending Thursday.

Ranging from presidential note cards to previously secret CIA reports, the documents describing Able Archer 83 offer fresh insight into a much studied but incompletely understood episode in the U.S.-Soviet rivalry. "This episode should be studied more because it shows that U.S. leaders might not have learned as much from the Cuban missile crisis [about avoiding accidental conflict] as they should have," Jones said.

In the current edition of the Journal of Strategic Studies, Israeli historian Dmitry Adamsky calls the 1983 war games "the moment of maximum danger of the late Cold War." Able Archer, he wrote "almost became a prelude to a preventative nuclear strike."

The March 1984 edition of Air Man Magazine , a rare detailed public account, called Autumn Forge "the biggest North Atlantic Treaty Alliance show of force of the year -- a test of military readiness in the context of NATO's deterrent mission." But the article emphasized the air lift, never mentioning rehearsal for nuclear war.

Even the troops on maneuver tried not to draw too much attention to themselves. At Dusseldorf Airport, the 45th Tactical Air Wing commander had his planes park away from the passenger terminal to keep a low profile. Most travelers, he was sure, were not even aware of troop activity at the airport.

But the Pentagon knew that the Soviets were monitoring his troops' every move. "The series of exercises are watched very carefully by the Eastern Bloc nations, just as we try to watch their exercises as closely as we can, to learn tactics and procedures," Air Force Maj. Gen. William E. Overacker told Air Man.