The Pope, Hope this helped !
Hello. Although you showed the book to which the question refers, you did not say which incident the question refers to, as there are many incidents covered in the book. This makes it impossible for your question to be answered, but I will try to help in the best possible way.
The main factor that points to the transition from old forms of war to new forms of war during the first world war was the use of technologies, mainly those driven by the industrial revolution, which gave the army a warlike power never seen before and allowed each army had access to fighter planes, tanks, submarines, toxic gases and others that did not exist in previous wars and that caused much greater destruction.
Had to look for the details and here is my answer.
"Saboteur" is actually a short story that was written by Ha Jin. And based on this story, the quote that best foreshadows the method of revenge by Mr. Chiu is this one: "I shall report you to the Provincial Administration. You'll have to pay for this! You are worse than the Japanese military police." Hope this answer helps.