Dave, she was talking for herself.
She found it persuasive, but I am sure she was persuaded by other evidence already, that the British people believed the war to be a necessary evil.
You will find no historian who challenges that view.

They were spreading deliberate lies about the Germans,
What lies? Justify your wild assertion.
and they were invoking the card of their supposedly superior breeding to persuade people in whose interests they were supposed to be governing to put their lives on the lives to satisfy their petty political and aristocratic egos.
Justify that assertion too!

Stevenson isn't persuasive to me.
Have you read the book?
Rag and I have. We found nothing to dismiss. How do you?