At the end of his life, according to Thomas, "he seems to have become convinced of the virtues of violence for its own sake", while "his influence over Castro for good or evil" grew after his death, as Fidel took up many of his views.
Menurut Thomas, menjelang akhir hayatnya Guevara "tampaknya sangat yakin dengan kebajikan dari tindakan kekerasan", sementara "pengaruhnya terhadap Castro, baik atau buruk", menguat setelah kematiannya, karena Fidel turut meyakini berbagai pandangan Che.