How long have we known the truth about the Cuban missile crisis?

I "agree" with the reader cited below by James Fallows in his continuing series on threat inflation and ensuing U.S. military engagements:

I said that nearly all the major official "threats" of the modern era proved in retrospect to have been hyped. Missile gap, Tonkin Gulf, WMD, etc. Reader JA immediately replied, "You left out terrorism." And reader AS wrote:

It's true that we came close to nuclear war during the Cuban missile crisis. But according to a well documented article in the Atlantic [plus others],  the missiles themselves were an inflated threat, i.e., according to US generals at the time did not materially hurt US security and could easily be traded, as they eventually secretly were, for US missiles in Turkey.