Argument Without End citations are historical transposition   Theres something in the Diem Era section stating that McNamara wrote X about motivations in Argument Without End  I would be leery of ascribing this as a contemporary statement in the s which is what the phrase indicates because McNamara wrote the book in  one of several he wrote on Vietnam long after the fact  Its obviously important as is the other work but I think it benefits from hindsight more than being reliable to the times and I would rather see it placed in its own LegacyCriticismwhatever section than being used as a reliable historical source for this article