Sheikh Abd al-Sattar Abu Risha was a powerful tribal leader in Ramadi, the capital of the Anbar province. He had initially supported the insurgency against the American occupation—that was the nationalist position among Sunnis. But by 2006, it was becoming clear that al-Qaeda in Iraq, the jihadi group led by Abu Musab al-Zarqawi and later Abu Ayyub al-Masri, was a greater threat to Sunni interests than the American occupation.

Al-Qaeda sought to impose a rigid Salafist interpretation of Islam, to create an Islamic state, and to eliminate all those—especially Shiites—who didn't conform to their ideology. The Sunni tribes, rooted in clan loyalty and local tradition, had no interest in al-Qaeda's apocalyptic vision.

What started as a local conflict between al-Qaeda and the tribes became the Awakening. Tribal leaders like Abu Risha began coordinating with American forces. The promise was simple: if the tribes helped fight al-Qaeda, the Americans would provide weapons, training, and payment. The Sunni fighters organized themselves into the Sons of Iraq, initially just a militia, but later integrated into the Iraqi security forces.

I watched this unfold from the perspective of a military advisor working with the tribes. What struck me most was the pragmatism. The tribal sheikhs were not suddenly pro-American. But they had decided that al-Qaeda was unacceptable. The tribal Awakening was not about ideology; it was about survival and power.

The numbers tell the story. By 2007, tens of thousands of Sunni fighters had joined the Sons of Iraq. In Anbar province, al-Qaeda's presence declined dramatically. The group that had controlled cities and run shadow governments was pushed into remote areas. The Awakening, combined with the American surge, seemed to have broken the back of the insurgency.

The Awakening became the template for the broader counterinsurgency strategy. General Petraeus and his team at Multi-National Force-Iraq recognized that you didn't have to defeat the entire insurgency militarily. You could peel away the nationalist insurgents from the jihadists, and then focus your military effort on the remaining extremists.

But the Awakening had a fundamental problem: it depended on continued American presence and American money. Once the Americans committed to a withdrawal, the logic of the Awakening collapsed. The Sons of Iraq members were mostly Sunni. When the Americans left, a Shiite-led government took over. The Sunnis who had fought al-Qaeda suddenly found themselves in a precarious position. Many were eventually absorbed into the Iraqi security forces, but many others were sidelined or marginalized.

By the time the Americans withdrew completely in 2011, the conditions were being set for the next phase of the conflict. The Sunnis who had turned against al-Qaeda were now threatened by Shiite militias and a Shiite-dominated government. Some of them would later join ISIS. But in 2006-2007, the Awakening seemed to be proof that the war could be won through a combination of military pressure and political reconciliation.