By Lennox Samuels

After years of war and insurgency, Iraqis have become almost inured to carnage. But incidents such as the suicide truck bombing that killed 80 residents near Kirkuk on Saturday have alarmed even some jaded citizens. The reasons: the disputed northern city of Kirkuk remains a major flashpoint in Iraq's political future, and the assault comes just days before U.S. combat troops are scheduled to permanently leave the country's cities and towns.

The stunning attack in Taza refocuses the spotlight on the nation's underlying sectarian tensions and exposes lingering anxieties about what will happen once the Americans withdraw on June 30, and whether the Iraqi Security Forces can adequately replace them.

Taza's residents are mostly Turkmen, but it lies just south of Kirkuk, where Kurds and Arabs continue to jostle for control. The attack has left Arabs pointing fingers at Kurds, Kurds blaming Arab insurgents, the Baghdad government accusing Al Qaeda, and Shiite and Sunni Arabs eyeing each other with suspicion.