A recurring theme in Brodsky's writing is the relationship between the poet and society. In particular, Brodsky emphasized the power of literature to affect its audience positively and to develop the language and culture in which it is situated. He suggested that the Western literary tradition was in part responsible for the world having overcome the catastrophes of the twentieth century, such as Nazism, Communism, and two World Wars. During his term as Poet Laureate, Brodsky promoted the idea of bringing the Anglo-American poetic heritage to a wider American audience by distributing free poetry anthologies to the public through a government-sponsored program. Librarian of Congress James Billington wrote,