Bergen, perhaps the most prominent contemporary commentator on al-Qaeda, has crafted an important single-volume history of the first decade of the “war on terror.” The Longest War examines the strategy and actions of Washington and its allies, as well as those of al-Qaeda and the Taliban. The book is intended as “an analytical net assessment” of the conflict, determining where both sides have succeeded and failed over the course of ten years.

Bergen has traveled widely, interviewed people on all sides of the conflict, and pored through a remarkable array of primary and secondary source materials. The book’s comprehensiveness is an asset—covering al-Qaeda’s early history, the 9/11 attacks and the early U.S. response, the CIA’s rendition program, the Guantánamo Bay detention facility, the Iraq war, homegrown terrorism, and much beyond that.

As could be expected for a volume with such a broad scope, Bergen reaches a number of conclusions with which readers may reasonably disagree. For example, while he views al-Qaeda’s strategic errors as more profound and lasting than those of the U.S. government, the book does little to illuminate al-Qaeda’s strategic thinking, making it difficult to compare the group’s accomplishments and failures to its overarching goals. Further, Bergen seems to assume that al-Qaeda cannot adjust or rebrand in the face of such tactical errors as backlash to the raw brutality it displayed in Iraq, when the group has in the past proven capable of learning from its mistakes.

Informed readers will doubtless find other points with which they disagree. But mere disagreement with aspects of Bergen’s argument is no reason to discount the work as a whole. The Longest War, eminently readable and appealing to both specialists and the general reader, deserves a place of respect in any book collection on terrorism and jihadism.