Potomac Institute for Policy Studies Senior Fellow Ambassador David Smith, a former US arms negotiator and expert on US-Russian relations, has been a sought-after source for commentary on the recent "spy swap" case.  Amb. Smith says plenty of unanswered questions about the swap remain. But he told the Associated Press that one obvious benefit of the deal is that freedom was obtained for four individuals imprisoned in infamous Russian gulags.  Click here to read the AP article including Amb. Smith's comments.