Here’s the key paragraph from this Economist story:

In the first six months of this year, 160,000 more Darfuris were displaced by the fighting. In the same period, one in every six convoys carrying humanitarian aid to the refugee camps was attacked; assaults on aid workers more than doubled compared with a year ago. The killing and burning of villages by the government-directed Arab janjaweed militias continue. More than 500,000 refugees are now cut off from supplies. And there are ominous reports that the Sudanese government, in what would be ethnic cleansing, is inviting Arab tribesmen from Niger and Chad to occupy the lands vacated by the refugees.

Can we call it “genocide” yet?