Good question …

… America When Will You Be Angelic? | Church Life Journal | University of Notre Dame.

Miłosz may not have been entirely aware that he was gradually turning away from the vatic tradition, remembering the effect it had on an idealistic generation of young men who gave their lives in a gesture of futile resistance and were buried in the wreckage of Warsaw. He was downplaying these bardic elements in the United States, perhaps relieved to put some distance between himself and that dark history, and he would eventually come to a new understanding as he was later drawn back to a free Poland. In the meantime, bardic prophecy and messianism wouldn’t do in a country that was increasingly turning to science and technology to answer age-old questions.