What event triggered the Soviet Union's initiation of communist paranoia in America?

The detonation of the first atomic bomb by the Soviets in 1949 was a significant event that intensified fears of communism in America. This event marked the beginning of the nuclear arms race and fueled national anxiety regarding the potential for Soviet aggression and the spread of communist ideology.

The successful testing of an atomic bomb by the Soviet Union demonstrated that the U.S. was no longer the sole nuclear power, which led to heightened concerns about national security and espionage, as many Americans feared that the Soviets could use their newfound power to expand their communist influence globally. This fear contributed directly to the rise of McCarthyism and an intensified focus on rooting out communist sympathizers within the United States, effectively solidifying the era's prevailing atmosphere of paranoia regarding communism.