I n post-invasion Iraq, Shiite death squads developed a signature tactic for dealing with their victims. Using power drills and nail drivers, they would drill holes in their victims’ torsos, heads, and hands. Then they would kill them. If that kind of thing had happened in, say, Burma, it would have been just one of many horrors detailed in an Amnesty International dossier, gathering dust. But this was Iraq, circa 2006. Over thirty thousand Iraqis had died in what had become a communal conflict, Iranian-funded proxy war against America, and extremist insurgency wrapped into one ticking time bomb. With the whole world watching, the U.S. had its hand on the detonator. And we needed to decide what to do.

Linda Robinson’s carefully researched Tell Me How This Ends is a probing look at how the decision to abandon traditional, enemy-centric warfighting in favor of a population-centric counterinsurgency strategy turned the tide in Iraq. With attention to detail across a sweeping cast of characters, Robinson describes how President George W. Bush and his administration were deadly wrong in their early decisions to disband the military and oust the Baathists, and how battle-lines were drawn across the military establishment as the situation turned sour. But all this is prelude to her exacting analysis of the 18 months following the installation of General David Petraeus as commander in Iraq and the implementation of the surge. During that time, Iraq metamorphosed from killing fields to a functioning society. Robinson makes a strong case that these changes would not have taken place without the shift to counterinsurgency strategy, and that the strategy would not have worked without the extra manpower of the surge.

It may sound counterintuitive, but for progressives, Petraeus’s victory is our victory. His strategy bucked traditional ideas, lauded by many conservatives, that we could win by outgunning and outmanning the enemy. Instead, Petraeus incorporated insights, such as the importance of legitimacy and privileging civilian life in order to gain hearts and minds, that progressives have been promoting for years. However progressives feel about the decision to enter the Iraq War, we should own its success.

To examine these conclusions more closely, we need to travel back to 2006. Daily headlines proclaimed the deaths of U.S. troops, often accompanied by a full-color photo of terrified, bleeding Iraqis surrounded by rubble and the detritus of yet another suicide bombing. The daily drumbeat of destruction had hardened political positions into two camps: "Stay the Course" and "Withdraw Immediately."

Dick Cheney and other administration figures pushed the "Stay the Course" strategy, though they offered no explanation for how more of the same was going to create peace. Instead, their argument was based on the costs of losing: If we withdrew, we would lose the war as well as our honor. Communal violence would become genocide. And we would inevitably have to return when violence spiraled across the Middle East and terrorists took up camp in the failed Iraqi state. Things were bad, they conceded, but leaving would make them even worse.

The pro-withdrawal camp did have a theory. "The cause for the violence is that the Americans are staying," said Nassar al-Buraie, head of the radical Sadrist bloc in Parliament. American troops were a target: reducing troops would, ipso facto reduce violence.

But al-Buraie added a twist absent from the American political conversation. "American military operations show that they are just protecting themselves and not the Iraqi people." By implication, should American forces focus on civilian security and not their own, public sentiment could turn, and support for insurgent violence could decline.

The U.S. faced two separate questions: How many troops should we devote to the war in Iraq? And how should we use these troops? But the political fight had conflated the two: Either we could continue fighting a kinetic war requiring us to maintain troop levels, or we could reduce troops in Iraq, and therefore use those that remained to train Iraqis, so that they could take control of their own security. General Petraeus stepped into this dichotomized conversation, and cut the Gordian knot.

Petraeus’s crucial step was to focus on the Iraqi people, a solution that grew from an immensely talented group of military leaders and academics whom Petraeus convened in early 2006 to craft a counterinsurgency doctrine. It is a pity that Robinson devotes few pages to this meeting of the minds, preferring to detail the battles that flowed from its conclusions. In an age where wars are won via publicity campaigns, public services, and election outcomes as much as on the battlefield, the rediscovery of counterinsurgency doctrine may be one of the turning points of modern military strategy.

Like all counterinsurgency strategies, Petraeus’s was premised on a simple idea: We cannot kill our way to victory. Instead of focusing on body counts–the typical metric of "enemy-centric" warfare–Americans would focus on protecting the Iraqi population. The military would provide security, then public services, to win their hearts and minds. Only with those preconditions secured could the United States press for a political solution.

While "political solution" often sounds like meaningless jargon, what it means is straightforward. Peace would only be attained when Iraqis made decisions about the balance of power in their country that all sides felt were reasonable enough not to try to change by force. And that balance of power depended, Petraeus realized, on paying attention to Iraq, in all its particularities. America would need to be attuned to issues of culture, honor, and power, from tribal councils to Baghdad ministries. Awash in jingoism and bombast, the conservatives who led the nation into the war had ignored these factors, assuming that respect for other cultures was somehow equivalent to moral relativism.

Petraeus’s strategy was deeply progressive. Not surprisingly: Sarah Sewall, director of the Carr Center for Human Rights Policy at Harvard University, was a driving intellectual force behind it, as were other leading progressive experts such as Janine Davidson and Montgomery McFate. They believed deeply in the need to protect the population in Iraq, just as progressives wished to do in Darfur, Rwanda, and Tibet. But as military as well as moral thinkers, they intuited that population protection was also crucial to winning modern war.

Finally, Petraeus was adamant that military strategy could only set the stage for political success, which would be achieved by other government agencies–yet another long-held progressive belief. The State Department needed the same billing as the Department of Defense, and all segments of government needed to contribute their comparative advantages. Chapter II of his counterinsurgency doctrine, "Unity of Effort," embodied the progressive desire for a more balanced national security strategy, one that re-apportioned many of the roles the Pentagon was not designed to serve, such as civil affairs and diplomacy.

Despite its provenance, Petraeus’s strategy was rejected by MoveOn and other leading progressive voices. They wanted to end the war, and to do so, they wanted to cut troops immediately. But a progressive approach to winning the war required captains spending days sipping endless cups of tea with tribal chieftains or negotiating with Iraqi politicians, and soldiers and marines spreading across scores of neighborhoods to provide the Iraqi population with security. That meant more troops in the short term. Unwilling to grant Bush a political victory, many progressives rationalized away their belief in principles such as preventing genocide.

Nevertheless, the strategy worked. American soldiers and marines changed the lives of Iraqis. Civilian deaths in the Ameriya neighborhood of Baghdad declined from around 26 a month in May to .6 in August. In the South Baghdad neighborhood of Dora, Iraqi murders plummeted from 563 in January 2007 to 35 in December. Nor were these neighborhoods so "ethnically cleansed" that there was no one left to kill–a military census taken in August 2007 makes clear that much of Iraq remains heterogeneous.

The progressive goal of withdrawal is on the verge of being achieved–but now, we will leave behind a more stable Iraq. To be sure, not everything can be attributed to the new American strategy. Al Qaeda in Iraq overplayed their hand, creating enemies among Iraqi Sunnis sick of the wanton killings. But the ensuing Anbar Awakening would not have occurred on its own, despite what many have said. As Robinson shows, it needed American manpower, persuasion, and money. It took the massive combined efforts of our military and State Department to force Iraqi President Nouri al Maliki and his increasingly sectarian, Shia government to allow Sunni "Sons of Iraq" to enter the police academy and be trained to protect their own neighborhoods against insurgents. It took U.S. money to pay them to switch sides, and U.S. military support to help them win. It required American troops to display almost super-human discipline as they patrolled side-by-side with Iraqis who had very likely been shooting at them just weeks before.