Which of these measures did americans fear was likely to lead to nuclear war with the soviet union?

There were several times during the Cold War when Americans thought there was a possibility of it going "hot", such as the Cuban Missile Crisis, and mistakenly thinking the other side had fired a nuclear weapon.

Social darwinism refers to the the theory that people who succeed in our economic system will one day out compete those who fail. one day the rich will out succeed the poor so we'll that there will eventually be no more poor