Who is Nikita S. Khrushchev from Thirteen Days; a Memoir of the Cuban Missile Crisis and what is their importance?

The Soviet Chairman who claims to have sent missiles to Cuba to keep the U.S. from attempting to overthrow Cuba's communist government as it once tries to overthrow the Soviet revolution, Khrushchev blusters for several days after learning the secret is out. He finally writes a long and emotional letter to JFK, pleading that they not succumb to "petty passions" or "transient things." Khrushchev has been in two wars and knows where it leads. Soviet missiles will not be used offensively, knowing the U.S. will respond in kind. Only lunatics or suicides could do what the Americans charge him with. The USSR wants to peaceful competition. Soviet ships carry no weapons since all weapons are already in Cuba.