PORTFOLIO / PENGUIN

Published by the Penguin Publishing Group

Penguin Random House LLC

375 Hudson Street

New York, New York 10014

USA | Canada | UK | Ireland | Australia | New Zealand | India | South Africa | China

penguin.com

A Penguin Random House Company

First published by Portfolio / Penguin, an imprint of Penguin Publishing Group, a division of Penguin Random House LLC, 2015

Copyright © 2015 by McChrystal Group LLC

Penguin supports copyright. Copyright fuels creativity, encourages diverse voices, promotes free speech, and creates a vibrant culture. Thank you for buying an authorized edition of this book and for complying with copyright laws by not reproducing, scanning, or distributing any part of it in any form without permission. You are supporting writers and allowing Penguin to continue to publish books for every reader.

Charts and graphs by Ali Croft

ISBN 978-0-698-17851-9

btb_ppg_140221977_c0_r2 p8UC0cXA9Cnp6jjfcW2BQnTsjUeXeuvkVK8EFKf+8Dj9OkVfPAcPeC8vlWzpRF9Q