War Quotes in Unbroken

How we cite our quotes: (Part.Chapter.Paragraph)

Quote #10

The 1929 Geneva Convention, which Japan had signed but never ratified, permitted detaining powers to use POWs for labor, with restrictions. […] Virtually nothing about Japan's use of POWs was in keeping with the Geneva Convention. (4.23.19-4.23.20)

Once again, we see how Japan shirks the rules of war. But isn't it odd that war has "rules" like this in the first place? Should "no war" be the first—and only—rule?