Even the Trump administration seems to grudgingly have concluded that breaching the Iran nuclear deal (JCPOA) was a mistake. More than two years after the U.S. exit, the deal still stands while the Trump administration is running out of options to force a re-negotiation. It is now so desperate it is seeking to convince the United Nations Security Council (UNSC) that it never quit the deal in the first place. The lesson to the U.S. is clear: Diplomatic vandalism carries costs — even for a superpower. The lesson to a prospective President Joe Biden is more specific: Rejoin the nuclear deal, don’t try to renegotiate it.

Secretary of State Mike Pompeo claims that UNSC Resolution 2231 defines the term “JCPOA participant” to be inclusive of the United States, and nothing the United States could do or has done can change this supposed legal fact.  According to Pompeo, even though the Trump administration repeatedly referred to its “withdrawal” from the JCPOA as a “cessation of its participation” in the agreement, UNSCR 2231 continues to define the United States as a “JCPOA participant” that can invoke the resolution’s sanctions snapback mechanism. 

The snapback permits a “JCPOA participant” to provide notification to the Security Council of a case of significant non-performance by a party to the agreement, triggering the automatic re-institution of former Security Council sanctions resolutions targeting Iran. No Russian or Chinese veto can prevent the reimposition of the sanctions contained in those resolutions. Only a resolution agreed to within 30 days that would undo the snapback — but the U.S. has the ability to veto such a resolution.

This is why the Obama administration cherished the snapback — if Iran were to renege on its nuclear commitments, the reimposition of sanctions would be swift and automatic. 

But this leverage was lost when Trump abandoned the deal in 2018 (the Presidential memoranda announcing the decision was even titled “Ceasing U.S. Participation in the JCPOA”). A senior Iranian diplomat told us at the time that Tehran was shocked that Trump would forgo this advantage. 

Now Trump is begging for a do-over. Despite the legal debate over Pompeo’s interpretation of UNSCR 2231, Trump’s gambit will prove less a legal question than a political one. The issue is not so much whether the United States remains a “JCPOA participant,” but whether the other members of the Security Council — and most prominently, its permanent members — will recognize the United States as such and allow Trump to issue a reverse veto to ensure the full re-imposition of U.N. sanctions on Iran. 

That is less likely to happen — and for an obvious reason: the Trump administration has spent the last three years squandering any international goodwill towards the United States, abandoning international agreements, strong-arming allies, and cozying up to dictators. It has threatened and cajoled its European allies to abandon legitimate trade with Iran or risk the wrath of punishing U.S. sanctions — all for the purpose of killing a fully functioning nuclear agreement that Europe views as essential to its security. Trump will need the sympathy of Europe’s permanent members to the Security Council. But no sympathy is likely to be forthcoming.

But even if Europe were to succumb to Trump’s pressure, it is unclear what objectives stand to be achieved. If, as Trump and his allies fear, a Biden administration would rejoin the nuclear accord, the snapback of U.N. sanctions is unlikely to pose a significant impediment to doing so, other than raising the cost to the United States for a return to the JCPOA. Nothing would prevent a President Biden to support the immediate reinstitution of UNSCR 2231. 

The danger, instead, is that Iran, having witnessed the malicious use of the snapback, will demand that any future resolution drop the snapback procedure. Considering that Iran will be weighing the merits of leaving the Nuclear Nonproliferation Treaty (NPT) and terminating its safeguards agreement with the International Atomic Energy Agency (IAEA) as a result of the U.N. snapback, the Biden administration would likely be forced to choose between eating that cost or escalating militarily against Iran in its first months in office. 

This underscores the real reason for Trump’s move: the U.S. is out of leverage when it comes to Iran. While U.S. sanctions have decimated Iran’s economy, they have not forced Iran to accede to Trump’s demands. Iran has neither begged for talks nor abandoned the JCPOA. Its posture remains essentially the same, immune to Trump’s best efforts to cause it to lash out to international approbation. 

Though immense pain, Iran has sapped the U.S. of its leverage while keeping its own intact. Tehran can (and has) scale back its commitments to the JCPOA in response to Trump’s actions, it can abandon the JCPOA or even withdraw from the NPT and terminate its safeguards agreement with the IAEA. These, and other options, remain in Iran’s arsenal, unused for the time being but ready to be deployed should the U.S. continue on its path of diplomatic vandalism. 

This is why Biden must dispel with any illusion that he can seek a renegotiation of the JCPOA on the back of Trump’s sanctions. If a Biden administration were to signal to Tehran that it will not seek a clean return to the JCPOA, then Iran will begin using the leverage it has kept in store.

If Trump succeeds in snapping back U.N. sanctions, Biden would not even be able to leverage the risk to Iran in international isolation, as Iran would be already isolated internationally by virtue of the U.N. sanctions. Biden’s sole recourse would be to threaten war with Iran — a terrible prospect for an incoming administration that will be fighting off a deadly pandemic, resuscitating a depressed economy, and operating under the promise of being different from Trump.

Trump overplayed his hand by thinking he could renegotiate the nuclear deal and is now begging for a do-over. Candidate Biden should take note and signal clearly already now that he does not intend to repeat this mistake.