Here's another extraordinary document release from Nate Jones of the National Security Archive at George Washington University. His research details, for the first time publicly, the NATO nuclear command post exercise called Able Archer, which was the culmination of a months-long effort to test NATO ground and air warfighting capabilities in Europe. Jones' work makes it clear that the Soviets were alarmed when the U.S. physically transferred more than 10,000 troops to Europe as part of the exercise. From a military standpoint, practicing rapid pre-deployment makes sense. But if your enemy is already interpreting your moves as the precursor to a first strike, it can be quite dangerous. Add to that the nuclear component, which involved actual nuclear aircraft, practice alerts, practice code validations and more.
As Jones notes, one of the after-action reports includes this "startling" observation:
There's still some debate about how scared the Soviets truly were, but we do know that Ronald Reagan came to believe, after Able Archer and a few other events, that he could no longer act passively with regards to non-proliferation. The policy, he wrote in his diary in early 1984, was too important to be left to the Pentagon. Only a president could save the world.