In a direct response to new sanctions passed by the U.S., Rouhani's warning challenged the Trump administration's confrontational policies. (Aug. 16, 2017) (Sign up for our free video newsletter here

Against all advice, President Donald Trump is insisting that the Iran nuclear deal negotiated by the Obama administration is so flawed that it should either be revised or scrapped altogether. He's flat-out wrong, and dangerously so.

Never mind that Iran has warned all bets are off if the U.S. pulls out of the agreement, or that America's allies are urging the president to leave well enough alone. It's obvious to them, as it should be to Mr. Trump and his advisers, that given North Korea's recent nuclear weapons and ballistic missile provocations, now is no time to unravel an internationally backed accord that may be our last best hope of preventing Iran from becoming the next rogue state bristling with weapons of mass destruction.


Under the terms of the agreement, Mr. Trump is required to certify to Congress every 90 days that Iran is holding up its end of the bargain. So far the president has twice assured lawmakers that Tehran is meeting its obligations. But in recent weeks he has signaled that he may not do so again. That would open the door for Congress to reimpose stiff economic sanctions against Iran that almost certainly would cause it to renounce the pact and resume enriching uranium in its race to build a bomb. That's exactly what we don't want to see happen. As long as Tehran continues to abide by the terms of the agreement, we should too, no matter how frustrated we are by its misbehavior in other areas.

At the U.N., Trump embarrassed the United States

At precisely the moment the world needed cooperation among nations, Trump lashed out on the world stage.

Mr. Trump has complained that even if Iran remains technically in compliance with the 2015 accord it has violated the spirit of the agreement by continuing to develop ballistic missiles and by supporting terrorism in the region aimed at destabilizing its neighbors. The president also worries that some of the restrictions the accord imposes on Iran's nuclear program will begin to expire in 2025. Yet while Iran's behavior in other areas remains threatening, such concerns don't justify ripping up a hard-won bargain that's likely to keep Tehran's finger off the nuclear trigger for at least another decade. There's no reason Mr. Trump can't seek to negotiate his concerns separately, to take effect alongside the 2015 agreement, rather than start the whole process over again from scratch. And there's no guarantee a second go-round on the uranium enrichment issue would be any improvement over what's already on the table, even if it did include Iran's missile programs and terrorism.

Moreover, renouncing the 2015 accord would send a terrible signal that the U.S. can't be trusted to keep its commitments. Mr. Trump himself has certified that Iran is complying with the terms of the deal, and we are getting what we want, which is for Iran not to build a bomb. Everything else is still negotiable, but it would be crazy to undo what's already been accomplished.

One agreement was never supposed to solve all our disputes with Iran. The nuclear accord was envisioned only as a first step toward improving relations with that country, which might then lead to greater cooperation on other goals. Mr. Trump's bellicose rhetoric is making that impossible by strengthening the hands of Iranian hard-liners and diminishing the ability of moderates to argue that better relations with the U.S. are possible and desirable. Mr. Trump calls the deal and "embarrassment" for the United States. It's not, but throwing it away would be that and worse.

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