Everyone should read Thucydides. The conflict between Athens and Sparta begat the fundamental book about war. The History of the Peloponnesian War is hard read. Let us then read Paul Woodruff's translation, On Justice, Power, and Human Nature . It is available used or new ($8-$15) on Amazon. If you prefer to read the whole thing, or a free translation, I will provide the chapter and verse. Read the introduction and the first section (i.1--i.22) by June 18. Come up with a question and drop it in the comments.