John Allen Gay makes the conservative case for a nuclear deal with Iran:

No nuclear deal will be perfect, and it would certainly be preferable for Iran to have no centrifuges and to come clean about all its past nuclear activities. But conservatives have always taken special pride in their emphasis on what is possible, not what is ideal. We do not let the perfect become the enemy of the good.

Gay makes a compelling case that reaching a comprehensive deal on the nuclear issue is the prudent, wise, and responsible thing to do. I very much hope that conservatives listen to what he’s saying, but recent experience and prevailing views about Iran on the right don’t give us many reasons to think that leading Republicans on this issue will take his advice. Gay observes that past Republican presidents have struck deals and made compromises with even uglier regimes than the one in Tehran, but these compromises were usually made over the loud objections of anticommunist hard-liners in their own party. When presidents from the other party attempted to make similar deals, the hard-liners were even more determined in their opposition. One need only think back a few years to the bizarrely contentious debate over New START to see how this works. Republican hard-liners were eager to portray even a modest arms control treaty as a giant sell-out to Russia, which it wasn’t, and they very nearly killed it. That wasn’t because the treaty was a bad one for the U.S., but simply because it was an agreement between a government that they loathed and an administration they wanted to oppose.

That points us to the differences between ideological hard-liners and temperamental conservatives. The former reject mutually beneficial deals because they usually reject the diplomatic engagement and compromise required to reach them, while the latter are quite willing to use diplomatic means to advance U.S. interests. Hard-liners are dead-set against reaching deals with Iran, even if they are actually better for all parties involved, because nothing short of total capitulation on the other side is considered acceptable. The only kind of negotiation that interests such people is negotiating for the other side’s surrender, which is one reason why they are so quick to denounce any compromise by our government in similar terms. It is in the nature of a hard-liner to see every deal as a betrayal and every compromise as a giveaway to the other side. If hard-liners saw the value in diplomatic compromises, they wouldn’t be hard-liners.

Conservatives should recoil from the mentality of such hard-liners for all the reasons Gay mentions. To do that, they first need to recognize that the hard-liners that are eager to sabotage the deal aren’t judging it on its merits, but have been determined to derail it from long before the moment when negotiations began. The hard-line position on the nuclear deal is an imprudent, unreasonable, and harmful one. Conservatives should want nothing to do with that, and should instead be open to a successful deal that advances both U.S. and Iranian interests and reduces the chances of conflict in the future.