A surge in time.

AS we went to press, President Bush was on the verge of announcing a "surge" of new troops into Baghdad. The idea is to devote enough troops to clear and then hold neighborhoods in the capital city. Our recent failed Baghdad security plan, Operation Together Forward, had American troops clearing neighborhoods and then leaving them to inadequate Iraqi forces, at which point they tended to revert back to lawlessness. The operation was nearly pointless, and Baghdad became more violent during its conduct.

The surge results from Bush's thorough reevaluation of his Iraq policy. Even before the midterm elections, he had (belatedly) begun to realize that our approach was not working. He fired defense secretary Donald Rumsfeld, an architect of the "light footprint" strategy that sought to minimize our presence on the ground and emphasize training the Iraqis. Reasonable enough in theory, the strategy amounted to standing aside as Iraq's violence mutated into a civil war that risks destroying any political progress in the country and tearing apart the security forces that we have been training. Bush also pushed toward the exits the two generals who shared Rumsfeld's belief in the light footprint, CENTCOM commander John Abizaid and his deputy in Iraq, Gen. George Casey. When Rumsfeld and Bush used to say that they weren't sending more troops to Iraq because the generals weren't asking for them, they were--unfortunately--telling the truth.

Bush is replacing Casey with Lt. Gen. David Petraeus, who got high marks in his previous tours in Iraq and had a large hand in writing the Army's new counterinsurgency manual. Generally considered one of the most talented generals in the Army, Petraeus has dissented from the light-footprint strategy and supports the surge. Bush has finally taken an approach more appropriate to his role as commander-in-chief--not mindlessly deferring to his generals, but picking ones who support his strategy and are committed to carrying it out.

The point of the surge is to provide enough security in Baghdad that the furies of revenge and hatred don't spin utterly out of control. Violence has radicalized Iraq, with cleric-thug Moqtada al-Sadr gaining ground as the civil war intensifies. So long as the sectarian violence continues unchecked, his power and influence will only increase, and Iraq will head toward a gruesome breakup in which Iran will likely effectively control the Shiite portion of Iraq and Sunni radicals their own rump--if, that is, Sunnis aren't cleansed from the country entirely. Neighboring countries might pick away at Iraq's carcass, U.S. prestige would plummet, and Iran and Saudi Arabia would again compete for strategic influence in the region by promoting their rival but equally noxious radicalisms.

It might still be possible to forestall this outcome, although it looks more difficult by the hour. We suspect many opponents of the surge simply believe the Iraq War is unwinnable. That is not an unreasonable position, but it is one they should declare openly rather than pretending that the status quo or the beginning of a drawdown is going to improve conditions in Iraq (force the Iraqis to "pull up their socks," in Rumsfeld's phrase).

There are several arguments against the surge. It has been said that it doesn't have a clear military objective. But clearing and holding populated areas is such an objective. It is also a standard counterinsurgency technique, and is right there in the new counterinsurgency manual.

It is said that the surge won't include enough troops because--operating on the standard ratio of 20 combat troops per 1,000 residents in counterinsurgency situations--it will take 120,000 combat troops to secure Baghdad's 6 million people. Of course, the Bush administration's record of providing enough manpower to Iraq is a poor one, and it is a safe bet that it will send fewer troops than would be ideal. It is difficult to find any additional troops because Bush left the post-9/11 military too small, a grave mistake he is only now beginning to rectify. All that said, the campaign is likely to start by concentrating on mixed Sunni-Shiite Baghdad neighborhoods where the U.S. will have the proper ratio of troops to clear-and-hold.

It is argued that a plan to secure Baghdad can't succeed without taking on al-Sadr (Bing West makes this case elsewhere in the issue). But that might be too big a bite at the moment, and would risk radicalizing more Shiites and toppling the government of Iraqi prime minister Nouri al-Maliki. Cutting al-Sadr down to size--unless he's reckless enough to confront us directly again--will necessarily be a delicate, touch-and-go task.

Surge critics note that the Iraq War is not just a military venture, but has to be won politically. True. That is why the Bush surge will include more economic aid and political benchmarks for the Maliki government to meet.

Finally, in a related point, some contend that the sectarian nature and incompetence of Maliki's government is the problem and that a surge won't address it. We have always counseled realistic expectations for post-Saddam politics in Iraq. But even with appropriately chastened expectations, Maliki's government is close to unacceptability. A surge resulting in increased security might give his government breathing space to find its footing, reaching out to the Sunnis and purging the corrupt and murderous sectarians in its midst. For now, the administration believes Maliki is committed to the new plan and will provide significant Iraqi forces to support it.

At this point, it should hardly need saying that there is no guarantee of success in Iraq. The surge is a risk. Its cost will be dear in increased American casualties. It holds political peril, too, for Republicans. In the short term, violence might increase, giving opponents an opening to say they told us so. If it fails altogether, the GOP will probably lose its historical advantage over Democrats on national security for some time to come.

But because the war is not yet lost, we must try to regain the upper hand. The surge is the only realistic option for success. Bush is brave and correct to embrace it. It should have been done before, and we can only hope that it works now.