New York – Iran’s foreign minister chose a pivotal week to come to the United States to argue his country’s case before Americans.

While Javad Zarif was ostensibly in town to address a UN meeting on sustainable development, he made clear during a 90-minute session Tuesday with US journalists and analysts, including this author, that his main purpose was to explain Iran’s concerns about the fate of the landmark nuclear deal he negotiated with the US and other major powers two years ago.

Hours before Zarif spoke, the Trump administration announced new sanctions on Iranian entities and individuals involved in Iran’s missile and other weapons programs. This followed an extremely grudging US recertification that Iran is complying with its requirements under the Joint Comprehensive Plan of Action (JCPOA).

The Trump administration did the same thing in April when it faced its first deadline to certify Iranian compliance to Congress.

Asked about this two-step, Zarif called it “a rather tired routine. Each time they are obliged to certify… they make sure that they do something negative.”

Even as it acknowledged that Iran was complying with the JCPOA, the Trump administration argued that Iran was violating the spirit of the deal. In fact, both sides have done so. Iran has continued to arrest Americans and dual nationals and hold them on bogus charges of espionage. While its ballistic missile tests do not violate the JCPOA, they are contrary to the intent of other UN Security Council resolutions. Iran also continues its military interventions in Syria and Yemen.

At the same time, the Trump administration has arguably violated the letter of the agreement by urging foreign countries, at the recent G-20 meeting in Hamburg, not to conduct trade with or invest in Iran. The travel ban the administration has repeatedly sought to impose on a half dozen Muslim majority nations also impedes Iran’s ability to benefit economically from the JCPOA – the main reason Iran accepted long-term curbs on its nuclear program.

The Trump administration has announced new arms sales to Iran’s Arab rivals across the Persian Gulf that give Iran a potent reason to keep testing missiles. Trump also sided with Saudi Arabia and the United Arab Emirates in their efforts to create a coalition against Iran — and beat up on Qatar, which has ties to Iran. Members and associates of the Trump administration talk cavalierly about “regime change” – a clear violation of numerous US obligations and another apparent effort to undermine foreign business confidence in the JCPOA.

During the presidential campaign, Trump called the JCPOA “a disaster” and suggested that he could have negotiated a far better deal. According to the New York Times, the president initially resisted the recommendation of all his top security advisers — Secretary of State Rex Tillerson, Defense Secretary Jim Mattis, White House national security adviser Lt. Gen. H. R. McMaster and Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff – that the US should provide the necessary recertification.

Having failed to repeal and replace Barack Obama’s signature health care program, Trump seems frustrated at also leaving Obama’s chief foreign policy achievement in place. But “repealing” the JCPOA unilaterally is not possible, given its multilateral nature as an agreement codified by the UN Security Council.

Replacing it is even more dubious.  All the other signatories to the agreement, including key US European allies, are firmly committed to implementation. If, absent major Iranian noncompliance, the US reneges, it would be isolating itself, not Iran.

The Trump administration has legitimate reasons to criticize Iranian policies in other areas, including Iran’s steadfast support for the murderous Assad regime in Syria and Iran’s arrest and conviction of American citizens on bogus charges of espionage. Among them is an 81-year-old former UNICEF executive, Baquer Namazi, and a naturalized American scholar from China, Xiyue Wang. In his meeting with reporters on Tuesday, Zarif tried to defend both policies but faced major pushback.

Still, there is no prospect that sanctions alone will resolve the wars in the Middle East or gain the release of jailed Americans without an equal if not greater effort at diplomacy.

Asked at an event on Monday by this analyst whether Zarif — who spoke regularly to Obama’s Secretary of State, John Kerry – had had any contact with the current occupant of that post, Zarif replied that “there are no communications between myself and Secretary Tillerson” but that the “possibility for interaction was there.”

On Tuesday, he added that he had not requested a meeting with Tillerson and did not plan to but “if there is a necessity” such an encounter could be arranged through the Joint Commission established to monitor the JCPOA. The commission meets at a lower bureaucratic level this week in Vienna but will likely convene with foreign ministers on the sidelines of the UN General Assembly meeting in September.

The Trump administration has said that it would like to extend the limitations on Iran’s nuclear program specified by the JCPOA.  The Atlantic Council’s Future of Iran Initiative has put forward innovative proposals for how this might be accomplished. At a minimum, it would require a stated willingness by the administration to offer incentives beyond those promised by the JCPOA.

To get to that stage, however, all sides must show they can abide by their existing commitments.

Zarif on Tuesday was vehement that more sanctions would not achieve any purpose beyond convincing Iranians of the unremitting hostility of the United States. He also warned US officials not to allow the US to be dragged more deeply into regional conflicts on the side of countries such as Saudi Arabia that have tried and failed to exclude Iran – the most populous and largest nation in the region — from any influence over events on or near its borders.

Successful negotiations, Zarif said, can never be zero-sum but must provide benefits to all parties. The JCPOA, he said by way of illustration, is a “not a deal that anybody loves” but was the best that could be reached under the circumstances. By casting doubt over whether the US will continue to comply with it, “the message the US is sending to the rest of the world is that you can’t count on the US to abide by its international obligations.”

Some members and associates of the Trump administration seem to be trying to goad Iran into walking away from the JCPOA. Their rhetoric encourages hardline factions in Iran that have also harshly criticized the deal.  Zarif indicated that Iran retained the option of leaving but said that US actions so far did not constitute significant non-compliance and “I don’t think we’re there yet.” He said the Trump administration appears to have “come to the realization that scrapping the deal would not be globally welcome.”

With all the other crises the US faces – both foreign and domestic – it would be the height of folly to try to blow up a non-proliferation agreement that is working. Iran is no angel, but the JCPOA shows that diplomacy can accomplish better results than war.

Barbara Slavin is director of the Future of Iran Initiative at the Atlantic Council.