The warmongers are all a fluster, as they won't get a chance (for at least today) to send someone else to fight an expensive and dangerous war on their behalf. So now they must criticize substantive diplomacy because Iran=bad. Ironically, the neo-conservative hawk's disdain for this deal is shared by the very people they are supposedly worried about: The Mullahs in Iran. They are kindred spirits of sorts, after-all if you've called someone evil for 36 years; it's awful hard politically to negotiate with them.
