What caused the red scare after World War 1?

The Red Scare after World War I was primarily fueled by fears of communism and radical leftist movements, particularly following the Bolshevik Revolution in Russia in 1917. The rise of labor strikes and anarchist activities in the United States heightened concerns about a potential communist uprising. Additionally, the growing influence of socialist and labor movements, coupled with paranoia about foreign ideologies, led to widespread suspicion and the crackdown on perceived subversives, exemplified by events like the Palmer Raids. This atmosphere of fear and distrust fostered a national sentiment against communism and radicalism, leading to the Red Scare.