D eclaring that “the deal is all signed” with Iran, as President Trump did today, is like shopping for a wedding dress after a good first date: It’s just too soon. A deal has an element of finality and permanence. A nuclear deal with Iran, for example, would require specific obligations, concessions, and verification measures, such as inspections, agreed to by all parties. What Iran and the United States are moving toward, with a signing ceremony scheduled for Friday in Geneva, is an agreement