It isn't clear exactly what provoked the unrest that preceeded the U.S. withdrawal. Some reports imply that the townsmen were inflamed by rumors that American troops had raided houses inhabited by unaccompanied women. (Sexual paranoia of this type provoked similar violence in Falluja a month ago).

The fact that the GIs from the 3rd Armored Cavalry were accompanied by Iraqi police officers may not have helped. Some U.S. officials have seized on the rehiring of Saddam's police as a quick, cheap solution to Iraq's security problems (as opposed to bringing in more U.S. troops), but this force of incompetents, thieves and once-upon-a-time torturers is not popular with Iraqis.

Still, whatever the reason for the riot, the most disturbing aspect of this incident is the way U.S. troops apparently cut and ran from the entire town after two Americans were slightly wounded.

If those reports prove true, then this was Mogadishu writ small.

And you can be sure that if word spreads that it is possible to drive American forces - with all their firepower - from a small town merely by throwing a few rocks and a single grenade, there will be similar, or worse, challenges to U.S. control all over Iraq.

Many more lives will be lost, American and Iraqi, and the accomplishments of American forces in Iraq undermined.

Of course, in an ideal world GIs would have non-lethal means of dispersing angry crowds.

But even the use of deadly force is preferable to the abandonment of a conquered town - an action bound to be read as cowardice or lack of resolve, and thus certain to undermine American authority at the most inopportune time.

There are at least two ways to lose Iraq very quickly:

One would be a campaign of serial, senseless atrocity - which won't happen.

The other would be a failure of nerve when it comes to using sufficient force to maintain order and American authority - and the Hit retreat looks like the first sign of just that.

Washington, take heed.