This exchange has been lightly edited for clarity
Jeffrey Goldberg: The primary criticisms [of the Iran nuclear deal] in, let's say more hawkish circles, are that the deal is too time constrained. It's unrelated and it does not deal with any of Iran's other malevolent actions in the Middle East. Trump says that these are the reasons that he wanted to get out of the deal. Put Trump aside for a minute. Do you think that the deal was tough enough?
William Burns: I think it was the best of the alternatives we could produce at that time. If we could have done a more comprehensive deal that included all of Iran’s threatening behavior in the Middle East, we would have done that. But we weren't going to get our closest European allies, as well as the Russians and Chinese, to agree to really strong international sanctions if the aims were that wide, at least right at the outset. Like any arms control process I've been involved in over the years with the Soviets and with the Russians, these aren't one-off agreements. You build on them over time. And so our expectation always was with this nuclear agreement with Iran that we were then going to have to build on it to try to extend the timelines in terms of some of the constraints on Iranian capacities to push back in other areas in the Middle East. We were just in a better position to do that. When we had united most of the international community around that set of goals, we were in a better position to deal with all of those other threatening Iranian actions.