said. Sani also dreads any military operation. Any attempt to rescue the girls by force will end in a tragic result -- it could be Nigeria's Beslan, he said, referring to the attempt to free hostages at a school in Russia in 2004 that left more than 300 dead, many of them children. Bargaining chips for prisoners, cash or concessions Shekau is not beyond negotiating with the Nigerian government, despite his apocalyptic rhetoric and frequent denials of President Goodluck Jonathan's legitimacy. According to the International Crisis Group, negotiations in Ivory Coast a year ago were on the verge of producing an apparent peace agreement that was to begin with a ceasefire. Then Shekau was designated a terrorist by the U.S. State Department and abandoned the talks. Sani believes Boko Haram targeted the girls to force concessions from the Nigerian government -- beginning perhaps with the release of Boko Haram followers from prisons. The fact Shekau said he would sell the girls and did not say he would kill them is a clear indication that negotiation is possible. Shekau's video is not going to be the last word from the group on the girls. And Sani suggests the notion of selling the girls should not be taken literally. People do n't buy girls in this part Africa, he said. But at least some of them may be traded for ransom money. Boko Haram has begun trading hostages for cash -- most