Answer:
To stop Cuba from making or launching missile.
Step-by-step explanation:
The letter that was sent by the then
United States president, J Kennedy, described his order to “quarantine” Cuba as “an act of aggression which pushes mankind toward the abyss of a world nuclear-missile war.”
Although, the first response from Khrushchev showed a threat, which meant that they were not going to succumb to the instruction in the letter that was sent to them from Kennedy.