From THE TWILIGHT WAR: The Secret History of America’s Thirty-Year Conflict with Iran by David Crist. Reprinted by arrangement of Penguin Press, a member of Penguin Group (USA), Inc. Copyright (c) 2012 by David Crist.

The twilight hours hold special significance in warfare. Your eyes are not acclimated to the changing light, and normal body cycles make soldiers less alert. I had this drilled into me as an aspiring marine corps officer. As dusk approached following a day of trudging around the woods of Quantico, Virginia, the last hour spent struggling to dig a fighting hole through a maze of roots with a small folding shovel that was frustratingly inadequate for the task, a captain suddenly hollered, “Stand to!” As the setting sun cast long shadows across the forest, I dropped into my partially dug pit and pointed my rifle out into the brush and trees. “You are always most vulnerable to enemy attack during the periods of morning nautical twilight and evening nautical twilight,” the instructor said, as part of a well- rehearsed lesson on tactics. “Dusk and dawn are transition periods,” he continued, with matter-of-fact delivery.

In 1987, when I attended the Basic School, a six- month- long school mandatory for all newly minted marine second lieutenants, many officers and senior enlisted had served in Vietnam. The lessons of that conflict, where the Vietcong frequently struck during twilight hours, had been seared into the collective memory of the service. Although with current technology a modern military can attack even on moonless nights or at the peak of the midday sun, the idea remains a valid military tactic. In July 2008, one of the worst attacks inflicted on the U.S. Army occurred just as the first hint of light appeared in the eastern sky of Afghanistan, when the Taliban struck a remote outpost, killing and wounding thirty- six soldiers. While no one attacked us during the training exercise in Quantico, the point stuck with me.

Twilight is an accurate metaphor for the current state of affairs between the United States and Iran. With no diplomatic ties and only occasional meetings in dark corners of hotel bars and through shadowy intermediaries, neither side has an accurate view of the other. The United States lacks clarity about Iranian leaders and the complex structure of the Iranian government. Meanwhile, Iran grows increasingly isolated and ignorant about the United States. This gray zone is dangerous. The threat of miscalculation is great and the military consequences can be grave. For three decades, the two nations have been suspended between war and peace. At various times, relations have moved from the light of peace to the darkness of war. But in the end, 2012 still looks remarkably like 1979, with the two nations still at loggerheads.

Both countries bear some culpability for perpetuating this conflict. The Iranian Revolution was born from anti- Americanism. The leaders who spearheaded that movement thirty years ago remain in power and see little need to change their stance. Hard liners in Iran reject the status quo of American supremacy in the region. With each chant of “Death to America,” they hope to reinvigorate the same fervor that swept them into power and tossed out an unpopular dictator, the shah of Iran, who had been imposed by the United States in a coup in 1953. While in this conflict the United States remains largely the good guy, it has not always been the perfect guy. Both Bush administrations dismissed Iranian goodwill gestures and refused to accept any dialogue that addressed Iran’s legitimate security concerns. The United States supported Saddam Hussein and his Arab bankrollers in a bloody war against the Islamic Republic that killed several hundred thousand Iranian soldiers. The mantra of regime change remains a frequent slogan in many quarters in Washington. Unfortunately, Iran’s response to these trespasses has invariably been to use the tools of the terrorist: an exploding car bomb on a crowded street or a plot to kill a diplomat in a popular Washington restaurant.

The research for this book, which included more than four hundred interviews, started in 1994 when I first traveled to the Tampa headquarters of CENTCOM to speak with officers charged with running this Iranian cold war from a worn, mazelike building at MacDill Air Force Base. I traveled to the backstreets of south Lebanon Shia neighborhoods and to the posh capitals of the Persian Gulf states interviewing Iranians and Arabs involved in the story. I went through my father’s papers and then the first of many linear feet of other personal papers and official records.

While the focus of the book changed as time passed and history continued to unfold, the essence of the story has remained: the two countries have been engaged in a largely unknown quasi-war since the Iranian Revolution in 1979. Six different American presidents have faced a seemingly intractable foe in Tehran. Each had a defining event that pushed the two countries like a pinball back and forth between rapprochement and war. What I found myself involved in on that April morning in the northern Gulf was the latest chapter in the ongoing saga of this shadowy conflict.

This story continues to unfold. As of this writing, Iran has threatened to close the Strait of Hormuz, and the two countries seem headed to the dark side of military conflict over Iran’s nuclear program. The saga is seemingly playing on an endless loop. After reading one recent memo outlining the Bush administration’s policies toward building an Arab coalition against Iran, as I relayed to the marine deputy commander at CENTCOM, John Allen, I could have interchanged the memo for one that had been written twenty- five years earlier as his predecessor grappled with the same enduring challenge of Iran. Iran’s quest for nuclear technology has heightened the stakes and the tension but it has not been a catalyst for the conflict.

I have tried to tell the most accurate and complete story I could of this three- decade- long conflict between Iran and the United States. The story begins with the seminal events of the Iranian Revolution that decisively turned the two countries from allies to adversaries and continues to the stories behind the headlines of today’s newspaper. The ideas presented in this book are my own and do not represent the views of the Department of Defense or the U.S. government.

The experienced American diplomat Ryan Crocker said to me in an interview, “For Iran, there is no such thing as history; it is all still the present. We are the most ahistorical and they are the most historical” of nations. In telling this story, I hope to rectify this fact. It is a story in which I have been a participant, dispassionate scholar, and, most recently, an adviser to senior Defense Department officials. It is a war of the shadows, largely unknown, arguably the most important and least understood conflict in recent history. It is the twilight war.