Once again, warlords ravage the countryside, undeterred by U.N. peacekeepers.

AFAMILIAR crisis is unfolding in one of the world's most miserable places. Rebel soldiers are camped outside the city of Goma, in northeastern Congo -- a region plagued by ethnic warfare and unspeakable violence against civilians for most of the past 15 years. Tens of thousands of refugees have been pouring in and out of Goma, where they are vulnerable to robbery, rape or murder at the hands of Congolese troops that are supposed to be defending them. Meanwhile, United Nations peacekeepers -- part of the largest such deployment in the world, with the mandate to use force to protect the population -- spend more time dodging stones from residents enraged by their fecklessness than fulfilling their mission.

In different forms, this same story has played out over and over in eastern Congo, despite multiple peace accords, elections and diplomatic interventions by the United Nations, the European Union and United States. The underlying problems remain unchanged. Ethnic Tutsis in the east -- lately led by a warlord named Laurent Nkunda -- say that they are defending themselves against militias led by ethnic Hutus from neighboring Rwanda. The Tutsis are supported morally, if not materially, by the Rwandan government. Congo's government has repeatedly pledged to disarm and disperse the Hutu militias but has failed to do so; instead, its badly disciplined army has been collaborating with them. The U.N. peacekeepers chronically fail to keep the peace, partly because their force of 17,000 is too small and partly because the troops, from countries such as India and Uruguay, are not competent.

The diplomats are back at work. Over the weekend, the British and French foreign ministers shuttled from Congo's capital, Kinshasa, to Rwanda and Tanzania; Assistant Secretary of State Jendayi E. Frazer has been traveling a similar path. The general idea is a good one: to get Congo's president, Joseph Kabila, to work out the core issues with either Mr. Nkunda, Rwandan President Paul Kagame or both. As leverage, the Western envoys have not only the extensive aid that flows to both Congo and Rwanda but also the option of dispatching an E.U. force to stiffen the U.N. peacekeepers. But Mr. Nkunda and Mr. Kagame may be hard to move. In addition to their security concerns, both leaders may be lured by eastern Congo's rich mines and forests, which local militias and invading armies have exploited in the past. Mr. Nkunda is unhappy about a $9 billion deal Congo struck with China, which would give Chinese companies mining rights in exchange for constructing badly needed road and rail links.

In the end diplomacy alone will not end this crisis or prevent the next one. European Union leaders, who decided Friday against dispatching an E.U. force, need to make clear to Mr. Nkunda and his backers that they will send in more troops unless he sticks to the cease-fire he has called and gives up the territories he has seized. At the same time, another attempt should be organized to disband the Hutu militias. Some militants could be allowed to return to Rwanda and participate in its political system. But the worst elements must be neutralized -- something that will require more action by a larger and more professional U.N. force.

© 2008 The Washington Post Company