Cold War
In the United States, there was a "Red Scare", and when the Soviets detonated their own atom bomb, there was a big political fallout and the United States government made everybody scared about communists. Famous people in many fields who had been Communist sympathizers in the past like Larry Adler lost their positions. Many actors were 'blacklisted' and so were not hired to act in movies, which ruined their careers. US Senator Joseph McCarthy was believed by many when he accused some important Americans of being communists, including some high government officials.