In 2006, everyone thought the US was losing the war in Iraq - except, it seemed, President George W. Bush and his administration. While the number of American casualties rose and Iraq edged into civil war, Bush continually assured the public that America was winning the battle with the insurgency.

But as Bob Woodward describes in his detailed history, The War Within: A Secret White House History 2006-2008, this was all presidential spin. Bush knew full well that America was losing: he just didn't have a clue what to do about it. Woodward's book, the fourth in his history of Bush at war, charts the administration's move from confusion to partial solution.

Bush had become trapped in a complex battle raging inside his own administration. Secretary of defence Donald Rumsfeld and the commanding general in Iraq George Casey wanted to reduce US forces in Iraq. They planned to hand over responsibility for security to the Iraqi forces. But many on the ground felt the Iraqis were not yet up to the task and more US troops were needed.

The War Within charts Bush's gradual acceptance of the second point of view. This ultimately led to the 'surge' in US troop numbers in 2007 and the consequent reduction of violence in Baghdad.

Woodward's book begins with more of the administration's squabbles that were included in the previous volume, State of Denial. But a new character appears, in the form of the US military. What follows is a gripping and fascinating drama that has all the twists, turns and plot reversals of a classical Greek tragedy.

Retired general Jack Keane, an influential soldier held in high regard in army circles, realises there will be no peace in Iraq unless more US troops are sent to stabilise the country. The trouble is, Casey and Rumsfeld won't hear of it and want to hand over responsibility to the ill-trained Iraqis as soon as possible.

Woodward describes how Keane believes Casey should be replaced by a forward-thinking strategist, General David Petraeus. But Keane faces two problems: the military top brass, citing the Vietnam-like horrors of becoming entangled in a civil war, want to bring the troops home as soon as possible. And they regard Petraeus, who was once on the cover of Time magazine, as a publicity hound.

To position Petraeus and instigate the troop surge, Keane must dance around the military chain of command and persuade the president to accept his point of view.

Woodward explored the flawed reasoning behind the war in his previous book and doesn't go into it here. The War Within has an apolitical view of the military - the politicians have led us into a war, so we have to work out a strategy to win. He asserts the military generally hold the politicians in low regard, realising their internal squabbles cost lives on the ground. Far from the usual gung-ho portrayals of generals, Woodward's book depicts them as concerned and human. The military top brass initially oppose the surge on the grounds that they don't want to see more of their men killed.

Bush comes out of it all badly. He did instigate the troop influx, but the idea came from the military. Woodward, who interviewed him for the book, says Bush distanced himself from the war's management, shifting responsibility to his advisers. He failed to assume the responsibilities of commander-in-chief. Worse, Bush failed to define the war's goals in sufficient detail.

The military has never been given detailed strategic goals to achieve in Iraq. The troop surge has brought a fragile peace to Baghdad. But the question of what victory in Iraq actually consists of has still not been answered. This question will be Bush's foremost legacy to president-elect Barack Obama.