Final answer:
McCarthyism fostered an increased distrust among Americans towards the Soviet Union, as it intensified the fear of communist infiltration in the U.S. government and society and led to the scrutiny of dissenting views as a sign of disloyalty or being 'soft on communism.'
Step-by-step explanation:
One effect of McCarthyism is that United States citizens displayed an increasing amount of distrust for the Soviet Union. During the early years of the Cold War, McCarthyism led to the rampant suspicion that Communist spies had infiltrated the U.S. government, particularly after claims by Senator Joseph McCarthy of Communists in the State Department. The spread of communism in China and the Korean War further exacerbated fears that the U.S. was vulnerable to communist influence, both from within and abroad. Subsequently, the investigations led by the House Un-American Activities Committee (HUAC) and the Senate Permanent Subcommittee on Investigations not only heightened anxieties but also stifled dissent and branded it as un-American. This climate caused many to conflate dissent with disloyalty, a view often associated with the idea of being soft on communism.
These actions notably affected the public's perception of and policy towards the Soviet Union, already considered the U.S.'s main rival and the leader of international communism. The Second Red Scare intensified concerns about the security of the nation from Soviet espionage, leading to an era where nearly every foreign and domestic policy decision in the U.S. was evaluated within the context of the Cold War. Thus, McCarthyism cultivated a deep-rooted distrust among Americans towards the Soviet Union amid an increasing effort to root out all perceived communist threats, often at the expense of civil liberties.