A work of prodigious research, "Cobra II" will likely become the benchmark by which other histories of the Iraq invasion are measured. Note the word invasion. Cobra II was the name United States commanders gave the operation to depose Saddam Hussein's regime. It is the story of the planning, execution and immediate aftermath of that invasion that is related by Michael R. Gordon, The New York Times's chief military correspondent, and Bernard E. Trainor, a retired Marine Corps lieutenant general and former military correspondent for The Times, in "Cobra II."

The book's title is therefore more apt than its subtitle — "The Inside Story of the Invasion and Occupation of Iraq" — which is only half accurate. Because the narrative essentially ends in the summer of 2003, this book is not a history of the counterinsurgency campaign that the United States has been waging in Iraq since then. It is, however, a penetrating examination of how and why the United States got itself into that mess.