Some Republican Iran hawks predictably want Tillerson to refuse to certify that Iran is complying with the nuclear deal:

Now, three months later, GOP senators are losing patience and want Tillerson to call out Iran for alleged violations of the deal and other assorted mischief, whether the administration’s internal policy review is completed or not.

Tillerson should ignore the senators’ letter. It would be a very serious mistake for the Trump administration to undermine the deal. That would gain the U.S. nothing while angering our European allies that helped negotiate the agreement. Maintaining restrictions on Iran’s nuclear program is in our security interests and it is good for the cause of nonproliferation in general. Refusing to certify that Iran is in compliance with the agreement would open the door to a new round of sanctions that could end up wrecking the deal all together. Iran hawks repeatedly tried and failed to sabotage the deal during the negotiations and then kept trying after the agreement was finalized, and now they are trying again.

The senators’ argument, such as it is, isn’t remotely persuasive. They try to confuse the issue by citing Iran’s “malign actions since the signing of the JCPOA,” but these have no bearing on whether the nuclear deal is in the national security interests of the United States. Whatever malign actions Iran may take elsewhere, keeping their nuclear program restricted clearly is in our interest. Refusing to certify the deal won’t do anything to reduce or hamper these “malign actions,” but it would jeopardize a successful nonproliferation agreement. As if to drive home how weak their case is, the senators refer to the brief detention of U.S. sailors in Iranian waters as proof of Iranian “aggression.” They neglect to mention that the diplomatic channels opened up by the nuclear negotiations allowed that incident to be quickly and peacefully resolved. The senators also assert that Iran has “consistently violated the terms of the JCPOA,” but this is simply false and the senators must know that it is. The reality is that continued sanctions relief is necessary to keep the deal on track, and only those that are dead-set against successful diplomacy with Iran (as Cotton, Rubio, et al. clearly are) would object to it.

None of the other parties to the agreement doubts Iran’s compliance, and the IAEA has confirmed that Iran is sticking to its part of the agreement. Aside from the obvious problems with refusing to certify compliance when Iran is demonstrably complying with the deal, the hard-liners’ maneuver is a reminder why it was always a mistake to give Congress a say in the process. The Corker-Cardin bill was an unnecessary piece of legislation, and requiring the Secretary of State to re-certify the deal every 90 days creates undesirable uncertainty about the agreement’s durability. Because of that provision, we are going to have to put up with periodic eruptions of Iran hawks’ ridiculous arguments against the deal every few months. We may hope that the saboteurs will continue their impressive losing streak, but with this administration there is a real danger that they might finally succeed in scuttling the successful nuclear deal.