Remarking in 2015 on the work, Kagan summarized the causes of war by quoting Thucydides: "You know, Thucydides has this great insight. I wish I could get people to pay attention – he has one of his speakers at the beginning of the war say, 'Why do people go to war? Out of fear, honor, and interest.' Well, everybody knows interest, and fear is very credible. Nobody takes honor seriously."