Middle East scholar Vali Nasr, of Johns Hopkins University, is "optimistic" that the US and Iran will re-enter some kind of nuclear deal. "I think the overall logic for both sides is that they want the deal," Nasr tells Ian Bremmer in the latest episode of GZERO World. Why is a new deal in the interest of both sides and what could it look like? Find out on the latest episode of GZERO World, airing on public television stations nationwide starting Friday, March 12. Check local listings.