Slaughterhouse 5: Conceding to War?

"'It had to be done,' Rumfoord told Billy, speaking of the destruction of Dresden.
'I know," said Billy." Page 198

       This is the first instance throughout the novel, aside from Billy failing to protest Vietnam bombing at a Lion's Club meeting, that Pilgrim takes a stance on what he saw. He often describes it as awful, or does not talk about it at all. Yet it is very rare that we see Billy reflect on his experiences as the aftermath of a necessary measure. He is obviously scarred from his experiences, such as remembering the "barbershop quartet" of German guards as they looked at the destruction of Dresden. Billy, despite this, is accepting the desolation as necessary to the cause of the war. His concession to war sort of had an odd characterization effect to me, showing how powerless this man felt at this point in his life, time traveling constantly and no longer caring about his death.