Final answer:
Communism was feared in the West due to the belief that it was a monolithic movement, causing concerns about communist infiltration and expansion.
Step-by-step explanation:
The fear of communism in the West was largely due to the belief that it was a monolithic movement. This means that communism was seen as a tightly controlled, uniform ideology that posed a significant threat to Western values and systems. The notion of a monolithic movement led to fears of communist infiltration and expansion, which fueled anti-communist sentiments in the West.