A promise, tested again.

• Author: Chafe, Zoe A.
• Position: Massacres in Darfur, Sudan - Editorial

"Never again." Sixty years ago a horrified international community, stunned by the realities of the Holocaust, invoked this statement to banish the specter of systematic killings. But with numbing frequency--after massacres in Cambodia, Iraq, Srebrenica, Rwanda, and elsewhere--it continues to be murmured in memory of those killed. Now, as we watch Africa's largest country hemorrhage human casualties, we are obliged to instead pose it as a question: "Never again?"

Darfur, a drought-weary section of Sudan, has been mired in violence since 2003, when rebels from several tribes began fighting the predominantly Arab national government for a greater share of national power and wealth. The Sudanese government has devastated rebel areas, empowering roaming militias to assist with the killings. Though an African Union peacekeeping force was dispatched to the region, it has lacked the mandate necessary to effectively intervene.

The result: in a region the size of France, with a total population less than that of New York City, as many as 450,000 people have died. Another 2 million Darfuris have been forced to flee their villages. Women are disproportionately affected, routinely attacked as they struggle to keep their families fed and hydrated.

But there is a backstory to this conflict. For decades, Arab nomads and African villagers alternately skirmished and supported each other as they raised livestock and tended fields, respectively, under resource-constrained conditions. At best, the two groups traded milk and meat for medicines and produce in local markets. At worst, when nomads allowed their camels to over-graze fields, or...