If you read only one book about America's quagmire in Iraq, this may be the one to read. Neither a neocon nor an orthodox liberal will like everything in it, but any reader should recognize the thoughtfulness and integrity with which George Packer wrestles with the subject.

One of the main strengths of The Assassins' Gate is that it is based on a extended engagement with the Iraqi people. The book grew from the author's friendship with a man named Kanan Makiya, an Iraqi exile whom Packer met over coffee from time to time in Cambridge, Massachusetts. Makiya, "a man with a large, balding head and soft, distracted features who always seemed to be in a hurry," had helped write a manifesto calling for a democratic and secular Iraq. It was Makiya who got Packer thinking seriously about the future of Iraq.

The book is based primarily on Packer's four journeys to Iraq, the first in mid-July 2002 and the last in 2005. Until it became too dangerous to do so, Packer stayed in the homes of Iraqis or in out-of-the-way hotels. He traveled widely in Iraq, talking to people of various religions and political beliefs, and avoiding press conferences and the gathering places of international media where groupthink crystallizes. Until 2005, he notes in passing, he never spent a night inside the Green Zone.

Because he is not an orthodox liberal, Packer takes the arguments for the war more seriously than others might. The first third of this book, in fact, discusses the ideological background for the war, the reasons given and the reasons not given. Iraq is the Rashomon of wars, he says. We may never be able to identify the “real” reason it happened. Even among the neocons, people like Paul Wolfowitz believed it was part of a mission to spread democracy around the world. Others had oil on their minds, or the Middle Eastern balance of power. The supposed threat from weapons of mass destruction, though neocons may have believed in it, was put forward as the justification for war because it was the easiest reason to rally around.

“My most heated and confounding arguments over the war occurred when there was no one else around,” writes Packer. “I would run down the many compelling reasons why a war would be unwise, only to find at the end that Saddam was still in power, tormenting his people and defying the world. The administration's war was not my war — it was rushed, dishonest, unforgivably partisan, and destructive of alliances — but objecting to the authors and their methods didn't seem reason enough to stand in the way.... To give my position a label, I belonged to the tiny, insignificant camp of ambivalently prowar liberals...”

Though Packer resists simple summaries, by the end of his time in Iraq you could say he believes that America won the war but lost the peace. Carefully prepared postwar studies were thrown away, billions of dollars were wasted, and the hands of well-meaning soldiers and administrators were tied by bureaucrats in Washington. The disbanding of the Iraqi army, the purging of Baathists, and the failure of the U.S. to stop the looting “led directly to the gutting and burning of all the key institutions of the Iraqi state.” The Iraqis complained that Americans, unlike the British, didn't know how to be good occupiers. “Americans were both too soft and too hard. Niceness and nastiness seemed to be two conjoined sides of their personality: Love me or I'll kill you.”

The Assassins' Gate is full of conversations with ordinary Iraqis, many of which are more subtle and creative than the statements of professional politicians. Despite the chaos and bloodshed, Iraqis — especially Iraqi women — were struggling to change their lives. “I want to travel,” says a young woman named Aseel after changing from traditional dress to a “resplendent royal blue” suit. “My mind doesn't match this society. I need more freedom.” No matter how long the U.S. occupation lasts, Packer argues that real victory in the Iraq war is still possible, and that victory depends on helping people like this toward a better future.