WASHINGTON -- On Dec. 14, the Ugandan army launched an attack on leaders of the Lord's Resistance Army (LRA) in northern Congo, targeting its commander, Joseph Kony.

Kony's epic career of murder has few equals. As both a rebel and a cult leader in northern Uganda, he led an army of stolen children and sex slaves, sometimes forcing his captives to engage in cannibalism and the murder of neighbors to sever ties of community and humanity. The LRA has been known to line roads with the decapitated heads of enemies. Terror and conflict displaced millions of Ugandans into camps. When Kony lost his havens in that country, he fled into the chaotic vastness of Congo, using the cover of peace negotiations to raise another force of terrorists and child soldiers.

For years, Uganda planned a complex military operation against the LRA in Congo. It would start with bombing runs by MiG fighters, then a helicopter assault, then the deployment of commandos, then the advance of two army brigades, forward deployed along the southern Sudanese border. Some units would liberate a nearby camp where families of LRA soldiers -- about 300 women and children -- were kept as hostages to prevent defections. Troops from Congo and southern Sudan would block escape routes.

But Uganda's troop deployments were delayed. Suddenly word arrived that Kony, fearing attack, would soon hold a meeting of LRA leaders, and order them to flee into the bush. Uganda decided to move ahead.

On the day of the attack last month, fog prevented the MiGs from flying. Instead, two helicopters went in first. The pilots reported seeing a group of LRA leaders, sitting in a circle of white chairs in a clearing. Scattered by the attack, the leaders attempted to escape toward a bridge -- where two more Ugandan helicopters opened fire.

Because of poor flying conditions, Ugandan commandos did not arrive at the site until 48 hours later. At first, they found nothing -- the LRA had carefully cleaned up evidence of the strike. But the Ugandans eventually found newly dug graves. Two defectors who had witnessed the attack said that some people had been shot, but claimed no knowledge of what happened to Kony. It is assumed that he survived, though he may be injured.

Ugandan forces are now pursuing scattered LRA units back into the empty vastness of Garamba National Park. But, as one Bush administration observer notes, "It is easier to run than to track."

On Christmas Day, in Faradje near the edge of the park, much of the town of about 25,000 residents was gathered in the evening to listen to a band. At first, they waved at the soldiers walking on the main street toward the market, assuming they were Congolese forces. In fact, they were they were hard-core LRA fighters who had flanked the crowd and began clubbing people to death with sticks. At least 100 houses were burned. Hundreds of people were killed or taken captive -- tied together by the waist and marched single file carrying looted goods into Garamba Park.

Though the initial results of the Ugandan military assault were disappointing, a number of starving LRA fighters have begun to surrender, and the pursuit of the rest is ongoing. The Ugandans, facing delays and difficult weather, have done a capable job. And regional cooperation has been exemplary -- the defense chiefs of Uganda, Congo and southern Sudan are in daily contact about the operation.

The Obama administration, however, will need to maintain the same intense diplomatic pressure that the Bush administration has applied to keep this coalition together. Congo's President Joseph Kabila was expecting a swift outcome, and may eventually face domestic pressure to end Ugandan operations on his country's soil. But there can't be any wavering now.

The success of this campaign is important because impunity for crimes against humanity is itself a crime. And justice, in this case, may send a pleasingly disquieting message to the likes of Sudan's Omar Hassan al-Bashir and Zimbabwe's Robert Mugabe: that mass killers do not always die quietly in their beds.

There is a natural and appropriate hesitance to wish death for any man. "Many that live deserve death," warned J.R.R. Tolkien. "And some die that deserve life. Can you give that to them? Then be not too eager to deal out death in the name of justice. ... "

It is a wise saying -- with some notable exceptions. And one of those exceptions is Joseph Kony, who has dealt out death to so many.