War

William J. Tharion. “The Fog of War: Decrements in Cognitive Performance and Mood Associated with Combat-Like Stress.” Aviation, Space, and Environmental Medicine, Vol. 76, No. 7, Section II, July 2005.

Low, Andreas, Peter J. Lang, J. Carson Smith, and Margaret M. Bradley. “Both Predator and Prey: Emotional Arousal in Threat and Reward.” Psychological Science, Vol. 19, No. 9, 2008.

Moore, J. “The Evolution of Reciprocal Sharing.” Ethology and Sociobiology, Vol. 5, 1984, pp. 5–14.

Moskos, Charles C., Jr. “Why Men Fight: American Combat Soldiers in Vietnam.” Trans- Action, Vol. 7, No. 1, November 1969, pp. 13–23.

Pepper, John W., and Barbara B. Smuts. “A Mechanism for the Evolution of Altruism Among Non-Kin: Positive Assortment Through Environmental Feedback.” Santa Fe Institute, Working Papers 0-12- 065, December 2000.

Pinker, Steven. “The Moral Instinct.” New York Times, January 13, 2008.

Rogers, Michael. “How Social Can We Get?” MSNBC, September 10, 2007.

Salo, Mikael, and Guy L. Siebold. “Cohesion Components as Predictors of Performance and Attitudinal Criteria.” Armed Forces & Society, Vol. 33, No. 2, 2007, pp. 286–295.

Shils, Edward A., and Morris Janowitz. “Cohesion and Disintegration in the Wehrmacht in World War II.” Public Opinion Quarterly, Summer 1948.

“Social Networks: Primates on Facebook.” The Economist, February 28, 2009, pp. 84–85.

Solomon, Zahava, Mario Mikulincer, and Stevan E. Hobfoll. “Effects of Social Support and Battle Intensity on Loneliness and Breakdown During Combat.” Journal of Personality and Social Psychology, Vol. 51, No. 6, 1986, pp. 1269–1276.

Stouffer, S. A., A. A. Lumsdaine, M. H. Lumsdaine, R. M. Williams, Jr., M. B. Smith, I. L. Janis, S. A. Star, and L. S. Cottrell, Jr. The American Soldier: Combat and Its Aftermath. Princeton University Press, 1949.

Trivers, Robert L. “The Evolution of Reciprocal Altruism.” Quarterly Review of Biology, Vol. 46, March 1971, pp. 35–57.

U.S. Department of Labor, Bureau of Labor Statistics. Census of Fatal Occupational Injuries, 2009.

Wansink, Brian, Collin R. Payne, and Koert van Ittersum. “Profiling the Heroic Leader: Empirical Lessons from Combat-Decorated Veterans of World War II.” Leadership Quarterly, 2008.

Whitham, Jessica C., and Dario Maestripieri. “Primate Rituals: The Function of Greetings Between Male Guinea Baboons.” Ethology, Vol. 109, 2003, pp. 847–859.

Wilson, Michael L., William R. Wallauer, and Anne E. Pusey. “New Cases of Intergroup Violence Among Chimpanzees in Gombe National Park, Tanzania.” International Journal of Primatology, Vol. 25, No. 3, June 2004.

Wrangham, Richard W. “Evolution of Coalitionary Killing.” Yearbook of Physical Anthropology, Vol. 42, 1999, pp. 1–30.

Wrangham, Richard W., and Dale Peterson. Demonic Males: Apes and the Origins of Human Violence. Houghton Mifflin, 1996.

Wrangham, Richard W., and Michael L. Wilson. “Intergroup Relations in Chimpanzees.” Annual Review of Anthropology, Vol. 32, 2003, pp. 363–392.

——— . “Collective Violence: Comparisons Between Youths and Chimpanzees.” Annals of the New York Academy of Sciences, Vol. 1036, 2004, pp. 233–256.

Wrangham, Richard W., Michael L. Wilson, and Martin N. Muller. “Comparative Rates of Violence in Chimpanzees and Humans.” Primates, Vol. 47, 2006, pp. 14–26.

Zegwaard, Gerard A. “Headhunting Practices of the Asmat of Netherlands New Guinea.” American Anthropologist, New Series, Vol. 61, No. 6, December 1959, pp. 1020– 1041.

Zhou, W. X., D. Sornette, R. A. Hill, and R. I. M. Dunbar. “Discrete Hierarchical Organization of Social Group Sizes.” Proceedings of the Royal Society B: Biological Sciences, Vol. 272, No. 1561, February 22, 2005, pp. 439–444.

Acknowledgments

FIRST AND FOREMOST I WOULD LIKE TO THANK MY wife, Daniela, for accepting my long absences and giving me such a wonderful home to come back to. Her editorial help was amazing and essential to the writing of this book. My parents, Ellen and Miguel, and my sister, Carlotta, provided much encouragement and heartfelt advice. Among my close friends Rob Leaver put a lot of thought into my manuscript and helped me with numerous conversations about men, war, and violence; and Austin Merrill gave me great advice about the overall narrative structure.

In the fall of 2007 I took a long walk in the woods with my dear friend Joanna Settle, and I told her about my experiences in the Korengal. Our conversation that bright, beautiful October day guided me in ways that are difficult to articulate but utterly essential to the nature of this book. Joanna passed away before she could read the results of our conversation, but her friendship and that of her husband, Ellis, are woven into almost everything I have ever written.

Many thanks must go to Graydon Carter of Vanity Fair, who had enough faith in me to underwrite multiple trips to Afghanistan when the story was not particularly hot and magazines were already tightening their belts. I would also like to thank my editor, Doug Stumpf, and his assistant, Christopher Bateman, for their ongoing help and enthusiasm in what became a three-year project. I am also deeply indebted to those at ABC Nightline for their hard work on the project: David Scott, Steven Baker, Maddy Sauer, Karen Brenner, James Goldston, Rhonda Schwartz, and Brian Ross. Kerry Smith, head of editorial content for ABC, was incomparable in her support and enthusiasm. My agent, Stuart Krichevsky, and his staff — Shana Cohen, Danielle Rollins, and Kathryne Wick — were critical in helping me with the book. Stuart’s advice on everything from editing to jacket design was almost always spot-on and I am very grateful to him. Cathy Saypol was also a source of editorial advice, publicity wisdom, and general encouragement. At Twelve, my editor, Jonathan Karp, gave me feedback early on that set the book in the right direction even though I couldn’t quite see it yet; thank you, Jon. Cary Goldstein did an amazing job generating interest in this book among booksellers. Mari Okuda allowed me many more last-minute changes than most authors are allowed, but she still got the book finished in time — I don’t know how. And Colin Shepherd was of great help in coordinating all the moving parts.

Throughout the writing of this book I was also making a documentary film on Second Platoon, and I must acknowledge the important roles of editor Michael Levine and associate editor Maya Mumma in the overall project. My researcher and fact-checker, Andrea Minarcek, did an incredible job excavating old studies on the behavior of men in combat, as well as current-day neurological research and psychological studies. Her hard work saved me from numerous errors. Within the U.S. military, I must point out the efforts of the Army public affairs office at Bagram and Jalalabad in getting me in and out of the Korengal Valley so many times — particularly Major Nick Sternberg, Captain Peter Katzfey, Sergeant First Class Jacob Caldwell, and Sergeant First Class Eric Hendrix. And of course none of this would have been possible without the support of the battalion commander, Lieutenant Colonel Bill Ostlund, as well as Captain Dan Kearney and First Sergeant LaMonta Caldwell of Battle Company. Lieutenants Matt Piosa and Steve Gillespie of Second Platoon, as well as Sergeant First Class Mark Patterson and Staff Sergeant Dave Roels were also great sources of information and support while I was out there. Safa Sediqi, my driver in Kabul, always got me everywhere safely and on time. I remember turning down a ride in a raging snowstorm because he promised that he was coming to get me… and indeed he did.

I must point out that without the friendship and acceptance of the men of Second Platoon this would have been a very different book and possibly not worth writing. My experience with them was one of the most gratifying of my life and changed me in profound ways. I think I finally understand the idea of brotherhood and how — without