WITHIN HOURS OF THE BOMBING of the al-Askariya shrine in Samarra on February 22, the media were filled with warnings that Iraq is sinking into civil war. Of course, almost any insurgency is, in a sense, a civil war, and sectarian violence has marked this insurgency from the very beginning. But the fact is that we are not facing a civil war in Iraq, with large scale military formations fighting one another along ethnic and sectarian lines. Moreover, we can very likely prevent this outcome, and, even better, make real progress toward victory.

What was striking, following the mosque bombing, was the evidence of Iraq's underlying stability in the face of attempts to undermine it. The country's vital institutions seem to have grown strong enough to withstand even the provocation of the bombing of the golden mosque.

In the wake of the bombing, it is true, militias took to the streets, and widespread sectarian violence occurred, killing and wounding many Iraqis. But not a single Iraqi political leader, including the volatile Moktada al-Sadr, endorsed an expansion of the violence. On the contrary, all joined to condemn it, to support government efforts to curtail it, and called on their followers to stop it. The Iraqi army and police were sent out to enforce curfews and stop traffic in many areas. Even in this crisis, they executed their orders, and shut down the great bulk of the violence within several days. Within a fortnight, Sunni leaders who had boycotted discussions aimed at forming a government

The tenacity of the Iraqi army is particularly notable. Iraqi soldiers are granted leave every month to hand-carry their salaries back home, in the absence of a reliable banking system. Especially for Shiites deployed in the Sunni triangle, this is a dangerous undertaking. Yet every month almost every Iraqi soldier "re-ups" by returning to his unit. This fact speaks volumes about the commitment of those soldiers and their professionalism in the face of the current dangers. If the situation began to spiral into real civil war, these Shiite soldiers would simply start deserting in droves, some of them to join up with Shiite militias. They are not doing so.

The continuing sectarian violence is, nevertheless, worrisome, as are the continuing tensions about the future nature and course of the Iraqi government. Together, these may ultimately undermine the foundations of stability. If the violence spreads, or other horrific terrorist attacks occur, the army and police may lose their effectiveness. The power of militias may grow beyond the point where the government and the Iraqi Security Forces can control them. Certainly, there is no basis for complacency. Iraq can still fail, with all the consequences that would follow.

President Bush has declared once again that the United States remains committed to stabilizing a democratic Iraq, and that American forces will stay there as long as necessary. He is right to reassert these commitments. The basic reason the Iraqi Security Forces and police have performed as well as they have is the presence of American troops.