Explanation: Many in the U.S. feared that the Soviet Union and its allies were planning to forcefully spread communism around the globe, overthrowing both democratic and capitalist institutions as it went. With the Soviet Union occupying much of Eastern and Central Europe, many in the U.S. perceived their fears of communist expansionism as confirmed. The U.S. also feared that communist agents had infiltrated the federal government. A massive witch hunt to root out communist sympathizers ensued.