What quotes highlight the moral ambiguity of O'Brien's experience in the novel?

I really like the below quote. It laments war yet implies that a certain necessity of the human spirit.

“I would wish this book could take the form of a plea for everlasting peace, a plea from one who knows... Or it would be fine to confirm the odd beliefs about war: it's horrible, but it's a crucible of men and events and, in the end, it makes more of a man out of you.

Great quote! I just can't seem to find it though. Got a page number?