By early 2007, the Iraq War was widely seen as lost. The violence was escalating. The sectarian conflict between Sunni and Shiite was intensifying. The Iraqi security forces were infiltrated with militiamen loyal to different sectarian groups. American casualties were high and rising. The American public was exhausted. Congress was in Republican hands and becoming skeptical.

In January 2007, President Bush announced his decision: instead of drawing down forces, he would increase them. An additional 30,000 troops would deploy to Iraq, bringing the total to nearly 170,000. General David Petraeus, a four-star general and counterinsurgency specialist, would take command of Multi-National Force-Iraq.

Petraeus brought with him a new doctrine. The previous approach had focused on "clear, hold, build"—clear an area of insurgents, hold it with troops, and build governance and security. But execution had often been incomplete. Troops would clear an area, but then move on to the next area, leaving the cleared areas vulnerable to insurgent return.

Petraeus's approach, codified in the updated Army field manual FM 3-24, put much greater emphasis on population protection. Rather than focusing on counting enemy dead (body counts), the metric of success became the security of the civilian population. Rather than concentrating forces, Petraeus dispersed them into smaller outposts in villages and neighborhoods. The theory was simple: insurgencies succeed by separating the population from the government. Counterinsurgency succeeds by re-establishing connection between the government and the people.

The implementation was brutal. Troops moved into neighborhoods, established patrol bases, and began a constant presence. They met with local leaders, provided security against criminal and insurgent elements, and tried to facilitate the restoration of local government and services.

The results, by conventional metrics, were impressive. Sectarian murders dropped from a peak of about 3,400 per month in December 2006 to about 1,000 per month by late 2007. The frequency of IED attacks declined. American casualties, which had peaked at 126 killed in November 2004, averaged around 70 per month during the Surge (still high, but showing a trend downward).

The Awakening, the shift of Sunni tribes against al-Qaeda in Iraq, occurred during the Surge period and was amplified by it. The combination of American military pressure and tribal revolt broke the back of the al-Qaeda organization in Iraq. By late 2008, al-Qaeda in Iraq had been pushed to the margins.

The statistical argument for the Surge was compelling: violence down, security improving, enemy capabilities degraded. The Surge became proof that counterinsurgency doctrine worked if properly resourced and implemented.

But there were problems that statistics couldn't capture. First, the Surge was fundamentally temporary. Keeping 170,000 troops in Iraq was unsustainable politically. The American public had turned against the war. Congress, which had become Democratic in the 2006 midterms, was pushing for withdrawal. The Surge bought time, but it didn't solve the problem.

Second, the security improvements did not translate into political progress. The Iraqi government remained corrupt and sectarian. The government forces included significant numbers of militiamen loyal to the Shiite leadership. The political reconciliation that would be necessary to create a stable Iraq was not happening.

Third, the Surge was predicated on continued American presence. The security improvements depended on American troops being present in neighborhoods and villages. Once those troops left, Iraqi forces would be responsible for security. But those forces were not politically neutral; they were sectarian instruments.

By 2008, it was becoming clear that the Surge had bought tactical success but not strategic victory. The enemy had been pushed back, but not defeated. The population was somewhat more secure, but not stable. The Iraqi government was still corrupt and sectarian, and American power could not fix that.

The Surge is remembered as successful because it reduced violence and because the military operation was well-executed. But it did not end the war. It did not produce political reconciliation. It did not create the conditions for a stable, democratic Iraq. What it did was buy time and reduce American casualties temporarily while setting conditions for later conflicts.