Shrine Bombing as War's Turning Point Debated

"In the end, stability was so weak that it only took the mosque bombing to break it apart," he concluded. "If the golden mosque hadn't done it, another bombing probably would have."

Even some in the military say their colleagues and commanders have misinterpreted the significance of the mosque bombing. "You have to understand the dome incident as being as much a manifestation of the weaknesses in our strategy and operational approach in Iraq than as some sort of causative tipping point," said Army Reserve Lt. Col. Christopher Holshek, a veteran of the Iraq war.

But the majority of military officers interviewed stood by the view that the shrine attack was the turning point in the war.

The impact of the bombing cannot be overestimated, said Army Lt. Col. James A. Gavrilis, an officer on the Joint Chiefs of Staff who served with Special Forces in Iraq. "The mosque bombing was a tipping point. . . . Sectarianism was a problem before, as it is now, but the bombing was a catalyst for increased sectarian violence."

Iraqi Shiite leaders have also cited the impact of the bombing. "The explosion of the holy shrine pushed the country into blind violence, in which tens of thousands of innocents were killed," said Grand Ayatollah Ali Sistani, Iraq's top Shiite cleric, in a statement last month. "No one knows but Allah when this tragedy will be over."

Before the attack, said an Army officer, "you could feel the changes and sense we were moving in the right direction." But after it, he said, Shiites were infuriated. "It was the catalyst that caused the Shiites to strike back hard and ramp up the cycle of sectarian violence," he said.

Another Army officer, a strategy expert, said Shiites had waited patiently to see if the United States could provide for their security. The bombing convinced them that it was not possible, he said, and they then turned to Shiite militias for protection.

But White, the former DIA analyst, said the bombing primarily changed the way U.S. commanders viewed the war they were waging. After that day, it became much harder for them to argue that there were enough troops, because the U.S. military was given the mission of containing Shiite militias, on top of its existing missions of countering the insurgency and training Iraqi security forces.

One Army officer who recalled buying into the optimism of late 2005 and early 2006, when he was a commander in Iraq, said that in retrospect, the situation was far worse than he and others understood it to be. He said it was the Samarra bombing that led him to believe that Iraq was indeed caught in a civil war. "What Samarra came to mean for me was a defining point in time, almost like a teaching point, where the real face of the Iraq war became clear," he said.

Staff researcher Julie Tate contributed to this report.