In the US after world war 2 which cause of anxiety was a common theme in invasion literature?

After World War II, a common theme in invasion literature in the U.S. was the anxiety surrounding the fear of communism and the perceived threat of foreign ideologies. This era saw a rise in stories depicting invasions by alien forces or hostile entities, often serving as metaphors for the fears of subversion and loss of American values. The literature reflected societal concerns about the Cold War, including paranoia about infiltration and the potential for societal collapse due to external threats. Such narratives often played on the anxieties of the time, illustrating a deep-seated fear of the unknown.