WITHDRAWAL of U.S. troops from Iraq's cities was the first significant step in fulfilling President Obama's campaign promise to end the now six-year-long war.
It is generally considered that the pledge to end the misbegotten conflict was the most important factor in Mr. Obama's victory in the 2008 election over Republican Sen. John McCain, who was firmly committed to carrying on the war indefinitely.
There is still some distance to go before the war is actually over and all of the some 134,000 U.S. troops there now come home. Full withdrawal is scheduled to take place by the end of 2011. That is what the United States has agreed upon with Iraq's occupation authority, the government of Prime Minister Nouri Kamal al-Maliki.
That withdrawal is scheduled to be completed prior to the commencement of truly heavy lifting in the 2012 U.S. presidential election campaign. The significance is that, based on withdrawal having been carried out or not, Americans will be able to judge Mr. Obama, presumably a candidate for re-election at that point, on the basis of whether he carried out his key 2008 pledge.
One hard part in Iraq will commence as the reduced U.S. troop presence in the cities - if not in the country at large - begins to be appreciated by various armed Iraqi groups. For the relatively newly trained Iraqi government security forces, it will be a test of their ability to maintain order in both the cities and the countryside, with U.S. troops ostensibly on the sidelines.
For various Iraqi insurgency groups, it will be a test of whether they can see wisdom in restraining themselves in order to obtain the total withdrawal of the foreign troops. It may be tempting for them to try to blow things up to embarrass the Maliki government and the United States, or simply to make an early effort to dominate the post-war power struggle.
If disorder begins to spread in Iraq's cities with U.S. forces in a more background role, it will be difficult for the United States to stand by and watch the order created - theoretically, at least - crumble in the face of renewed violence.
At the same time, it will be absolutely necessary for the United States to do just that. After six years, in the wake of an invasion that was pointless in the first place and which Americans are now thoroughly sick of, it is obligatory that the Iraqis cope with their own problems and the United States stays out of the way.
The American death toll in Iraq stands at more than 4,300. The financial cost is virtually incalculable, particularly if one includes the likely cost both of refitting our armed forces and of dealing with the severe physical and emotional wounds of the Americans who have fought there.
It is definitely time to wrap it up. Tuesday's withdrawal of U.S. forces from Iraq's cities is a very important, positive first step.