While North Korea’s reckless behaviour in pursuit of a nuclear weapons program has diverted international attention in recent weeks, another crisis-in-the-making should be regarded with equal concern.

What the world does not need right now is another nuclear crisis on top of efforts to build a global consensus to deal with North Korean brinkmanship.

And yet that is what is at risk from a policy tug-of-war in the Trump administration between those who believe Iran is living up to its obligations – however imperfectly – under a 2015 agreement to freeze its nuclear program and those who want to toughen its provisions.

US President Donald Trump has described the agreement, known as the Joint Comprehensive Plan of Action (JCPOA) – a centrepiece of his predecessor’s foreign policy – as the “worst deal ever”.

Under a Congressional mandate, the administration is obliged to certify the agreement every 90 days. On the advice of Secretary of State Rex Tillerson, Trump has done this twice, but a festering issue has bubbled to the surface ahead of the next certification deadline on October 15.

Administration hawks are pushing for a renegotiation of the original agreement – something that Iran would almost certainly resist, along with other parties to the deal.

These include, apart from the US, the remaining four permanent members of the UN Security Council plus Germany. China and Russia could be expected to be especially resistant.

Any US action to withhold certification or seek to alter the terms of the JCPOA risks prompting an international crisis in which the US would find itself isolated from its natural allies. And all this at a moment when global consensus is required to deal with North Korea.

Gulf states, led by Saudi Arabia, might be pressuring the US to toughen its stance against Iran more generally, but if the JCPOA became a casualty of these pressures, an even more chaotic Middle East would be a likely result.

Israel’s campaign againstthe JCPOA has been relentless, and in this it finds itself aligned with Saudi Arabia in ways that have the potential to shift regional alignments.

In the Arab vernacular: “the enemy of my enemy is my friend”.

In the US, concern about the administration’s commitment to the JCPOA has stirred arms control experts to counsel against steps that would jeopardise an agreement, however flawed, that appears to be working.

Thomas Countryman, who served as assistant secretary of state for international security and nonproliferation from 2011 to 2017 (during which the JCPOA was negotiated), warned this week of risks to the agreement.

In a commentary for CNN, Countryman wrote:

The president campaigned on rash promises, including plans to tear up the deal, and he made it clear this summer that he still expects to pull out of the “worst deal ever”.

Sadly, he may do so even without any evidence to justify such an extreme course of action.

Countryman noted that just last week the International Atomic Energy Agency had reported that all parties to the JCPOA – including Iran – are in “full compliance” with the agreement.

This is the eighth time the agency, in its regular reports mandated by the JCPOA, has confirmed that the nuclear deal is working.

This expert assessment is not being challenged directly by members of the administration antipathetic to the agreement, but an attempt appears to be underway to reinterpret the JCPOA to take into account Iran’s behaviour more broadly.

This was never the intention.

US Ambassador to the UN Nikki Haley gave voice to this strand of administration thinking in a speech earlier this month to the American Enterprise Institute (AEI) in which she questioned Iran’s adherence to the spirit of the agreement. Haley said:

Judging any international agreement begins and ends with the nature of the government that signed it.

Does it respect international law? Can it be trusted to abide by its commitments? Is the agreement in the national interests of the United States.

Haley answered her own question by launching an ad-hominem attack on Iran more generally, including criticism of its continuing development of a ballistic missile capability.

The ballistic missile issue is not dealt with in the JCPOA, rather in a separate UN resolution.

Haley’s suggestion that certification of Iran’s compliance with the JCPOA should be shifted to Congress is problematical since that body overwhelmingly opposed the deal when it was negotiated. She told the AEI:

Under the law, if there was such a referral Congress has 60 days to consider whether to reimpose sanctions on Iran.

During that time, Congress could take the opportunity to debate Iran’s support for terrorism, its past nuclear activity and its massive human-right violations.

This process would almost certainly destabilise the JCPOA.

In an editorial, the New York Times forcefully expressed its misgivings:

If Mr Trump blows up the nuclear deal, then what? None of the original opponents of the deal, in or out of Congress, including Mr Trump, have offered any plausible alternative for restraining Iran’s nuclear ambitions. Without such an alternative, a reckless decision to honour a reckless campaign promise invites Iran to pursue an unfettered path to a bomb. And if deals with the United States cannot be trusted, North Korea will have one more reason to keep pursuing its nuclear program.

In all of this one might have sympathy for Tillerson, who has been tasked with seeking to toughen provision of the JCPOA in consultation with America’s allies.

Tillerson is reportedly arguing for an extension of the freeze on Iran’s nuclear enrichment program beyond the 2025 and 2030 limits specified in the agreement. Those discussions will continue on the sidelines of the UN General Assembly in New York next week when foreign ministers of the JCPOA signatories have been asked to convene to discuss the issue.

Indications are that the US will have some difficulty persuading the representatives of China, Russia, the UK, France and Germany to revisit the JCPOA.

One option being canvassed by the US is for a separate set of agreements that would seek both to limit Iran’s missile development, and extend the “sunset” provisions on its nuclear enrichment program.

New French president Emmanuel Macron has expressed lukewarm support, but it seems unlikely Germany’s Angela Merkel would fall into line if such a step risked the overall agreement struck after two years of painstaking negotiations.

Indeed, this week Merkel proposed talks on the North Korea crisis along lines of the negotiations with Iran:

I could imagine such a format being used to end the North Korea conflict. Europe and especially Germany should be prepared to play a very active part in that.

From an Australian perspective, no purpose would be served at a moment when it wants the focus to remain on North Korea by a separate crisis over Iran’s nuclear ambitions.

Australia might be “joined at the hip” to the US, in Prime Minister Malcolm Turnbull’s words, but when it comes to an issue like America’s threats to blow up the JCPOA, Australia would be advised to endure a bit of separation anxiety.