Here's the good news about Darfur: we know it is doable to force the regime in Khartoum to back away from its genocidal divide-and-conquer strategies. We know this because the U.S. helped do it once already: it led international pressure that forced Khartoum to a peace accord and power-sharing agreement with southern Sudan in 2005. If we want to preserve the peace in the south, stop the genocide in Darfur, and prevent Genocide Round Three from happening in Sudan's eastern Beja region, we need to remember the lessons of the last seven years.

Here's the genocidal strategy Khartoum has repeatedly employed: when rebel groups form in Sudan's provincial areas – an understandable reaction to a government that takes callous disregard for its countrymen to new depths – it arms ethnically or regionally-based militias and turns them loose to rape and kill civilian populations, forcing millions to flee their homes. It aims to create as many splinter groups as it can, in order to keep its enemies weak.

Then, when it has managed to stir up widespread violence and human rights abuses, it cynically tries to bill the whole thing as an internal ethnic conflict, hoping to pass off genocide as anarchy. But to buy this line would be to blame the spark of pre-existing ethnic tension, rather than the truckload of gasoline which the Khartoum regime systematically poured on.

They did this in southern Sudan, against Christian and animist populations, for decades. The tide began to change just before the turn of the millennium, when the New Sudan Council of Churches initiated a people-to-people peace process (focusing on traditional leaders and civilians rather than rebel commanders) which did hard, painstaking work to heal ethnic and regional divisions within southern Sudan – divisions which had prevented the region from negotiating from a position of strength. At the same time, a wide outcry from diverse groups in the U.S., including conservative Christians and human rights advocates, motivated the Bush administration to initiate a full-court diplomatic and economic press. After a range of delaying tactics, Khartoum signed onto a peace agreement in 2005.

By that time, they were already into round two of the genocidal strategy, in Darfur: this time arming the Janjaweed militias, drawn largely from groups that consider themselves Arab, against populations that consider themselves ethnically African.

Khartoum didn't think we'd care if they slaughtered Muslims. It is a good and hopeful thing that they were wrong.

But we need not just to care, but also to remember the lessons of the last seven years. So far Darfur peace efforts have consisted of sporadic, drive-by diplomacy which has allowed Khartoum to continue fanning the violence in Darfur, while putting off the international community with false promises of reform, mixed with belligerent bluster. Exhibit A is the failed 2006 Darfur Peace Agreement, which got the buy-in of only one rebel group and gave no seat at the table to civil society.

Peace talks are re-convening in December – read this excellent, concise analysis and let your government know you want us to get our diplomatic act together, now.

Elizabeth Palmberg is an assistant editor of Sojourners.