Michael Frayn (b. 1933) is a British playwright whose politically and socially charged works emerged during Margaret Thatcher’s premiership (1979–1990). Influenced by the dominant ideology and political crises of the Thatcher era, his plays often reflect themes associated with neoliberalism. Copenhagen, one of his most significant plays, unfolds within the historical contexts of World War II, the Cold War, and the rise of quantum physics. By offering new interpretations of surveillance and control, the play engages with Foucauldian concepts of power/knowledge. This study aims to analyze the key Foucauldian concepts of governmentality and biopolitics, which serve as analytical tools for understanding the socio-political conditions of the Thatcher era. These concepts, critically examined by Michel Foucault, occupy a central place in modern theoretical discourse. The analysis of Copenhagen through the lens of governmentality and biopolitics reveals how Frayn re-reads Thatcher’s rule in Foucauldian terms and demonstrates how these concepts evolved in that historical period. Furthermore, the role of scientific knowledge in shaping these Foucauldian ideas—both in the context of the play and in Thatcher’s Britain—is explored. This perspective suggests that applying such theoretical frameworks to literary texts can open a window into the political and social truths of the time in which the work was written.