Over the weekend, the undecideds in Congress got another confidence-builder from Iran on the nuclear deal that Barack Obama and John Kerry insist they support. If Congress approves the deal, it carries legal weight in the US, at least for the next 16 months or so until the next President takes office. The Iranian parliament must be rushing to provide the same level of legal commitment, right? Right? Er … no, not really:

President Hassan Rouhani said Saturday he opposes a parliamentary vote on the landmark nuclear deal reached with world powers because terms of the agreement would turn into legal obligations if passed by lawmakers.

Rouhani told a news conference that the deal was a political understanding reached with the five permanent members of the U.N. Security Council and Germany, not a pact requiring parliamentary approval. The deal also says Iran would implement the terms voluntarily, he said. …

“If the Joint Comprehensive Plan of Action is sent to (and passed by) parliament, it will create an obligation for the government. It will mean the president, who has not signed it so far, will have to sign it,” Rouhani said. “Why should we place an unnecessary legal restriction on the Iranian people?”

Well, maybe because the Iranian mullahs have illegally pursued nuclear weapons for the last 20 years or more? Color me skeptical, but it doesn’t exactly offer confidence in this deal if the Iranian government is strategizing on how to keep it from being legally binding on them while Obama insists that it should be legally binding on us. In their eyes, this is just “a political understanding,” not a commitment. That should have the US hitting the brakes immediately and reconvening the P5+1 (or the EU3+3, or whatever formulation they have used of late) to define exactly what this deal is before anyone proceeds any further along the path of giving Iran $140 billion.

Regardless of whether Iran thinks it’s a deal or not, a guest column in the Washington Post last Friday advised the US to bind ourselves to it. Otherwise, wrote Seyed Hossein Mousavian, the Iranian mullahs might radicalize their nation:

Indeed, the successful conclusion of the nuclear talks has led to the development of a new pragmatism in Iran, personified by prominent decision-makers who have more sober and practical views on foreign and domestic policy. This phenomenon has seen the joining of political figures who hail from historically opposing camps, namely the moderate Rouhani and the principalist speaker of parliament, Ali Larijani. This heretofore unseen alliance is a significant development in Iran’s political landscape and has positioned pragmatism as a palpable political force in Iran.

What should be of chief importance to Western policymakers is that the prospect for a more cooperative Iran rests with them reciprocating Iran’s pragmatic outreach proportionately. For their efforts thus far, the pragmatists, led by the president and the speaker, have garnered vociferous criticism from hard-liners, who accuse them of having given far too many concessions on the nuclear program. If there was nothing to show for these concessions, pragmatism would be marginalized and Iran would be forced to retract from its commitments. Thus, durable sanctions relief is critical to ensuring a more amicable Iran. …

Congress’s overriding the deal would surely lead to radicalism once again at the expense of pragmatism in Iran. Moreover, the nuclear deal has the potential for far-reaching positive implications for the volatile Middle East region and for Iran’s relations with the West.

On that we agree, although perhaps not in the way Mousavian intended. The former spokesman for the Iranian nuclear negotiators pretends that the Iranian mullahs have not radicalized Iran already, and have since 1979. Americans of my age have clear memories of what that meant in 1979 and the 1980s: Americans being taken hostage, and in Beirut more than one of them killed, plus the spread of Hezbollah across the Middle East. Moreover, the “volatility” of the Middle East in recent decades comes in large part because of Iran, which has deployed proxy terrorist armies (primarily Hezbollah) to undermine governments in Lebanon and Yemen, and bolster tyrants like Bashar al-Assad. Their pursuit of nuclear technology came as part of that radicalization, which aims to bring the Middle East under the thumb of Tehran in a modern Persian Empire, putting its radical Shi’ite Islam in place of self-determination — especially in Israel.

Obama and Kerry want us to balance all of that recent history and state-sponsored terrorism against a piece of paper — to which the Iranians won’t even legally commit themselves. Someone’s getting taken in this exchange, but it doesn’t have to be Congress.