Two months before he hosted a conference on narcotics at the White House, President John F. Kennedy smoked marijuana with his mistress, American socialite Mary Meyer, according to retired history professor Michael O'Brien, who wrote the book "John F. Kennedy: A Biography."

During the experience, Kennedy apparently realized that pot might prevent him from adequately handling a national-security crisis.

Meyer, a close friend of Jackie Kennedy's and the ex-wife of a top CIA agent, reportedly came over to the White House on the evening of July 16, 1962, after Kennedy joked that he wanted to smoke cannabis. O'Brien wrote that Washington Post executive Jim Truitt said he provided Meyer with the pot:

The president smoked three of the six joints Mary brought to him. At first he felt no effects. Then he closed his eyes and refused a fourth joint.

'Suppose the Russians did something now,' he said. Kennedy allegedly told Mary that the pot 'isn't like cocaine,' and informed her that he would get her some cocaine.

That same month, the Soviet Union signed a secret agreement with Cuba's Fidel Castro to deter any future invasions by the US after the Bay of Pigs. Nikita Khrushchev began supplying Cuba with Soviet nuclear missiles, other weaponry, and military personnel.