Four years ago this week, as American troops made their first, triumphant entrance into Baghdad, joyous Iraqis pulled down a giant statue of Saddam Hussein. It was powerful symbolism — a murderous dictator toppled, Baghdadis taking to the streets without fear, American soldiers hailed as liberators.

After four years of occupation, untold numbers killed by death squads and suicide bombers, and searing experiences like Abu Ghraib, few Iraqis still look on American soldiers as liberators. Instead, thousands marked this week’s anniversary by burning American flags and marching through the streets of Najaf chanting, “Death to America.”

Once again, tens of thousands of American troops are pouring into Baghdad. Yesterday the Pentagon announced that battle-weary Army units in Iraq would have to stay on for an additional three months past their scheduled return dates.

Mr. Bush is desperately gambling that by stretching the Army to the absolute limits of its deployable strength, he may be able to impose some relative calm in the capital. And he seems to imagine that should that gamble succeed, the Shiite-dominated government of Prime Minister Nuri Kamal al-Maliki will, without any serious pressure from Washington, take the steps toward sharing political power and economic resources it has tenaciously resisted since the day it took office a year ago.