Answer:
Nikita Khrushchev
Step-by-step explanation:
It all started in 1960 when a U-2 spy plane was shot down while photographing some Soviet military bases. After this event, the Soviet leader, Nikita Khrushchev, was waiting for an apology from the United States for the incident. It never came, and it was there when MAO interpreted this as disrespectful towards socialist nations, so it demanded that Khrushchev face war with the Americans. He refused to meet this demand, so MAO concluded that Khrushchev's cowardice would make Russia and China socialism as weak. This ended up breaking the ties of this relationship.