There had been a spate of UFO sightings over the Soviet Union, and President John F. Kennedy was downright worried.
It was the height of the Cold War, and JFK was afraid that a UFO over the USSR might be mistaken for a missile—and prompt the Russians to launch missiles of their own.
On November 12, 1963, Kennedy dictated a memo ordering that the US prepare to share sensitive information about UFOs with the USSR, so that there would be no apocalyptic mistakes. The president was shot dead in Dallas a mere 10 days later.
The memo reads: “It would be very helpful if you would have the high threat cases reviewed with the purpose of identification of bona fide as opposed to classified CIA and USAF sources. It is important that we make a clear distinction between the knowns and unknowns in the event the Soviets try to mistake our extended cooperation as a cover for intelligence gathering of their defense and space programs. I would like you to arrange a program of data sharing with NASA where unknowns are a factor.”