The photographs were disturbing. American soldiers grinning at the camera, posing with naked Iraqi prisoners. A human pyramid of detainees. Prisoners on leashes. A prisoner covered in feces. Soldiers punching, kicking, sexually abusing detainees. The images, taken by the guards themselves and later leaked to the media, spread across the world in April 2004.

Abu Ghraib was Iraq's largest prison, located just outside Baghdad. After the invasion, it became the main detention facility for suspected insurgents and al-Qaeda fighters. Thousands of Iraqis passed through its gates. The facility was overcrowded, understaffed, and chaotic.

What happened there became one of the defining scandals of the Iraq War. The abuse was not incidental; it was systematic. The photographs showed that it was treated as normal activity by some of the guards. They took pictures the way tourists take vacation photos.

The investigations that followed traced the problem upward through the chain of command. The immediate perpetrators were members of the Military Police unit guarding the prison. But investigations by the Red Cross and military inspectors showed that the abuse was encouraged by interrogation pressure from military intelligence. Detainees were subjected to "stress and duress" techniques designed to break them psychologically. Sleep deprivation, stress positions, loud music, extreme heat and cold. When these techniques didn't work, Physical punishment began.

Where did the authorization come from? Investigations eventually reached Donald Rumsfeld, the Secretary of Defense. It became clear that the Bush administration had deliberately created a legal framework that allowed aggressive interrogation. The Office of Legal Counsel, under Jay Bybee and John Yoo, had issued opinions stating that torture was legal under certain circumstances. Rumsfeld approved interrogation techniques that went beyond what military doctrine had previously allowed.

The military courts-martial that followed prosecuted the low-ranking soldiers—the ones who pulled the trigger and took the photos. Eleven soldiers were court-martialed. Six were convicted. But the higher-ranking officers and civilian leaders who created the environment were never held accountable in a legal sense.

The strategic damage was profound. Abu Ghraib became the symbol of American conduct in the war on terror. Around the world, the images were seen as proof that Americans were no better than the dictators and terrorists they claimed to be fighting. The photographs were used in terrorist recruitment videos. They were cited in investigations of American war crimes. They became the most powerful propaganda tool the insurgency could have asked for.

The investigation also revealed that Abu Ghraib was not unique. Similar abuses had occurred at other detention facilities. The Bagram airfield in Afghanistan had seen similar conduct. The CIA was running secret detention facilities with interrogation practices that went beyond anything the military was doing. The broad strokes of what was happening were known at senior levels of the government.

Abu Ghraib marked a turning point in how Americans saw their own government. For many, the photographs revealed something fundamental about how the post-9/11 security state had changed America. The war on terror, justified as a defense of American values, had led to the abandonment of those values.

By 2008, the photographs had been analyzed by human rights organizations, investigated by military and civilian prosecutors, and debated endlessly by commentators. They had damaged American soft power in the Muslim world for years. And they had become a historical marker: the point at which it became clear that something essential had been lost in the pursuit of security.