Daniel Drezner in Foreign Policy:
1) It will purge 300 from your system. The ancients were all about the purging, and this classic will help you void the non-so-classic film. True, the two stories don’t overlap all that much. And true, I like homoerotic goofiness as much as the next hetrosexual. That said, it’s a crying shame that far more people have seen that mockery of Greek history than read… any Greek history. Alas, even modern criticisms of 300 wind up infected with stupid and ignorant Thucydides references. So read some Thucydides and you can enjoy Gerald Butler’s abs Lena Headey’s abs 300 on a more refined, absurdist plane.
2) You will earn Star Trek street cred. Want to know where the Star Trek franchise gets the names for 90% of its obscure alien species? Look no further than Thucydides. Just one read and you’ll discover the source of the Cytherians, the Battle of Tanagra, and other names that will bore amaze your friends.
3) You will recognize some recurrent patterns in history. Thucydides will help one develop a better appreciation for life in 5th century BC, but it will really help one develop an appreciation for the aspects of human nature that are unchanged through time.
… explanations of each (and more) follows in the article …