It is a great challenge to write an account of an ongoing war that, at least officially, remains a secret. I decided to write this book because I wanted to present my own reporting and conclusions about the shadow wars that have been waged over nearly a dozen years since the September 11 attacks. By now, the contours of the wars in Iraq and Afghanistan are fairly well known, but the public knows far less about the secret wars in countries like Pakistan and Yemen. I have tried to shed as much light as possible on events that still require more research and public discussion.

The book is the result of hundreds of interviews in the United States and overseas, both during my years as a national security reporter and during my book leave from The New York Times.  I began covering national security issues in the Spring of 2001, just months before the September 11 attacks, and made my first trip to Afghanistan in early 2002. Since then, I have made several reporting trips to Afghanistan, Pakistan, Iraq, and the Horn of Africa.

I have tried as much as possible to convince the people whom I interviewed to speak for the record. I also conducted scores of interviews on “background,” where I allowed sources to speak anonymously in exchange for their accounts of American military and intelligence operations, the vast majority of which remain classified. Although this is hardly ideal, I believe it is a necessary to ensure that trusted sources are able to speak candidly at a time when there is a broad government crackdown on information about the wars beyond declared war zones.

I am deeply indebted to the many people in several different countries who gave up countless hours of their time to let me interview them. They trusted me to tell their stories, and this is their book as much as it is mine.