Supporters of the Joint Comprehensive Plan of Action (JCPOA) are wringing their hands at what might become of the deal under a Trump administration. After all, during his election campaign, Trump dismissed President Obama and Secretary of State Kerry’s signature deal as one of the worst ever negotiated. During Obama’s White House meeting with Trump, the president reportedly urged Trump to reconsider his opposition to the agreement.

This hand-wringing about Trump’s approach to Iran diplomacy fits an unfortunate pattern in which politicians and their partisan bench prefer to blame the other party than international adversaries for diplomacy’s failure.

The real problem with the Iran deal—despite it being loose, porous, and temporary nature—is that the Iranian government itself has no intention to abide by it. Put aside questions about Iran’s ballistic missile work—Kerry arguably conceded that against the backdrop of last-minute Iranian brinkmanship—and the refusal of Iranian officials to allow inspections of military sites, a red line international inspectors have chosen not to test.

Iran’s overproduction of heavy water is a violation that has now occurred twice. The international community has allowed Iran to sidestep the violations by exporting its excess heavy water, even if that meant U.S. taxpayers were essentially subsidizing and rewarding Iran’s illegal nuclear activity.

Now, Behrouz Kamalvandi, the spokesman of the Atomic Energy Organization of Iran, has said Iran will reduce its exports of heavy water even though there is no evidence that Iran will stop producing such large amounts of heavy water. This is worrisome, of course, because heavy water reactors can produce plutonium as a byproduct. The Iranian argument that limits on heavy water are a suggestion and not mandatory will have no traction once Kerry departs the State Department.

This means that the first Iran crisis of the Trump presidency is looming. Iran will, once again, be in violation of the Joint Comprehensive Plan of Action. It will now be up to Trump to determine whether he will ignore or rationalize the violation despite his campaign rhetoric or take action. If he follows the process laid out by the agreement, Russia and perhaps China will defend Iran despite the blatancy of Tehran’s violation. That leaves Trump with a choice: stand down and lose face—an action which will do as much harm to U.S. credibility as Obama’s decision not to abide by his own red lines in Syria—or punish Iran unilaterally. If the Iranian press is to be believed, the Islamic Republic has now thrown down the gauntlet and started the countdown to what may be the first diplomatic crisis of the Trump administration.