We have all heard that negotiating with Iran about its enrichment program without first securing Iranian suspension of that program would be bad because Tehran could use those negotiations as cover to keep enriching. Since Iran is enriching now, this is not a cost to negotiating without a suspension. The above is also true because, absent such a suspension, the UNSC would maintain its sanctions on Tehran and could impose new ones.
Oh, and Josh blogs a lot, if you haven’t noticed. I doubled his salary.