And I always thought alienation, or alien nation, was a community of ETs located somewhere on earth that hadn't been clearly identified as of yet!  

Alienation is a fundamental, recurring theme in literature that explores the emotional and psychological disconnection individuals experience from society, or their cultural heritage.  It serves as a powerful, often tragic, lens for exploring modern existence, focusing on themes of loneliness, isolation, and the struggle for identity within a fragmented world. 

The importance of alienation in storytelling includes:
Character Development and Motivation: Alienated characters often serve as conduits for exploring internal conflicts, such as the struggle to align personal identity with societal expectations (e.g., Death of a Salesman, Invisible Man). This creates high-stakes drama as characters confront their own "invisibility" or lack of self-awareness. 
Social and Cultural Commentary: Writers use alienation to critique oppressive, rigid, or indifferent societies. It highlights the tensions between individual identity and conformity, often showcasing the "minority of one" fighting against the majority. This is also used to explore the nuances of cultural identity, such as the tension between assimilation and heritage, as seen in The Woman Warrior. 
The "Alienation Effect" (Defamiliarization): Popularized by Bertolt Brecht, this technique intentionally disrupts the audience's emotional immersion in a story to promote intellectual, critical engagement with the text. It breaks the "fourth wall" or uses unnatural elements to prevent the audience from blindly accepting the narrative, forcing them to analyze the social and political messages presented. 
Thematic Depth: Alienation allows for exploring existential questions about the absurdity of life, the limitations of language, and the failure of communication, particularly in Modernist literature. 
Modernity and Urbanization: It reflects the 20th-century experience of disconnection from a rapid, mechanized, and urbanized world.