Anthropology: "War and Gender" in Carol R. Ember and Melvin Ember, eds. Encyclopedia of Sex and Gender: Men and Women in the World's Cultures. Kluwer/Plenum and Human Relations Area Files, 2003.
Anthropology: Panel on precontact North American warfare at the American Anthropological Association conference, Chicago, November 2003, discussant.
Psychology: "The Importance of War in the Gendered Socialization of Aggression," presented at G. Stanley Hall Symposium on Gender and Aggression, Williams College, 2001.
Gender Studies: "War" in Michael S. Kimmel and Amy Aronson, eds., Encyclopedia of Men and Masculinities, Santa Barbara: ABC-CLIO, 2004.
Economic History: "War and Economic History" in Joel Mokyr, ed., The Oxford Encyclopedia of Economic History, 2003.
Political Economy: The Real Price of War: How You Pay for the War on Terror [tradebook], New York University Press, Sept. 2004.
"The Worldwide Lull in War" [Op Ed] (CS Monitor 5/14/02: 9).
International Relations, Tenth Edition [textbook], NY: Pearson Longman, 2012; coauthor Jon C. Pevehouse.
War and Gender: How Gender Shapes the War System and Vice Versa [book]
Winning the War on War: The Decline of Armed Conflict Worldwide [book]