Glenn was almost an excuse to invade Cuba.

If Glenn's capsule returned to Earth, operation "Dirty Trick" was prepared. According to rumors, the Pentagon planned to exploit his death as justification for an invasion of Cuba by attributing any incident to Cuban electronic meddling. Military strategists at the Pentagon considered blaming Fidel Castro if astronaut John Glenn failed to return to Earth when he launched into space aboard a Mercury capsule on February 20, 1962.

Operation Dirty Trick was the proposed plan, and it was intended to "give irrefutable proof that, should the MERCURY manned orbit trip fail, the guilt lies with the Communists et al Cuba," according to long-secret documents made public Wednesday. The planners proposed in a document dated February 2, 1962 that this could be achieved "by fabricating various pieces of evidence which would establish electronic interference on the side of the Cubans.