I’ll give brainliest please answer the ones that are blank

21. In 1962 the Soviet Union began to secretly install missiles in Cuba to launch attacks on U.S. cities. The confrontation that followed, known as the Cuban missile crisis, brought the two superpowers to the brink of war before an agreement was reached to withdraw the missiles.23. Isolationism or non-interventionism was a tradition in America’s foreign policy for its first two centuries.24. was afraid that communism would spread to South Vietnam. It decided to send money, supplies and military advisers to help the South Vietnamese Government.

You can double check... tried my best..

sorry if its not correct