Stephen Walt identifies what he calls a paradox in reactions to the deal with Iran:

Thus, the paradox: Many supporters of a diplomatic deal don’t believe the danger of a “nuclear Iran” is all that momentous, while opponents of the current deal think Iran’s nuclear program poses a grave and imminent threat. One would think the former would be more relaxed about recent progress, while the latter would be more enthusiastic. But that isn’t the case: Those with a moderate view of the nuclear danger are much happier with the deal than those who (logically) ought to be more interested in anything that constrains what Iran is able to do.

It’s an accurate observation of the very different reactions to the interim deal, but I’m not sure that there is a paradox on either side of the debate. It’s not truly a contradiction in the hawkish position to have an irrational and exaggerated fear of Iran’s nuclear program and to react negatively to any diplomatic agreement with Iran. If Iran hawks genuinely believe that the Iranian regime is suicidally fanatical and cannot be deterred, they should view any accommodation with the regime as a terrible mistake no matter how small or temporary it may be. The flaw in their view isn’t that it contradicts itself, but that its core assumptions are total nonsense. That’s why Iran hawks have responded so illogically by rejecting the deal as appeasement. Iran hawks should be more pleased with a deal that slows Iran’s nuclear program than anyone, but their view of the program is so doom-laden that they have long since passed the point where they could ever be satisfied with a diplomatic accord. Their assumptions about Iranian capabilities and intentions are wrong, and so their preferred policies end up being equally misguided.

Along the same lines, supporters of the interim deal and of engagement with Iran more generally believe that a negotiated solution to the nuclear issue is both possible and desirable, and have responded to the result of the Geneva talks as positively as one would expect. There is no contradiction is viewing Iran’s nuclear program as a manageable problem and endorsing a productive step in managing it. Supporters and opponents of the deal are also distinguished by very different estimates of how much power the U.S. and its allies have over what Iran does with its nuclear program. Hawks assume that there is some means available to compel total Iranian capitulation (or perhaps even force regime change), while supporters of engagement assume that there are some things that the Iranian government cannot be forced into doing. That is why the former issue fantastical demands that will never be accepted, and the latter dismiss maximalist demands from our side as an obstacle to reaching a final agreement. Hawks look at Iran as a foe to be forced into submission, and their opponents see it as a country with its own interests that can and should be accommodated within reason. No, I’d say there is a terrible consistency to the hawkish view.