Trumps decision yesterday to withdraw from the Iran nuclear deal is a global tragedy likely to unsettle an already volatile Middle East anda world in some disarray.

Trump has pulled out of the deal not because it was flawed, but because it was working as intended and this posed an insurmountable obstacle to potential military strikes on Iran. As a consequence, Trumps decision will worsen relations with Europe, destabilise the Middle East, complicate negotiations to reverse North Koreas nuclearisation and damage the global nuclear order.

Explanations for Trumps Decision

There are two structural explanations and a host of personal reasons for Trump pulling out. Most importantly, the neoconservative hawks, back in charge of US foreign policy, are determined to follow theWashington playbookof militarised responses to foreign crises. They believe in using US power to remake the world in their image, disdain arms control treaties, view the need for allies as evidence of US military weakness not diplomatic strength and want to eliminate regimes not weapons. To dedicated ideologues, multiple past failures do not prove the policys inherent flaw, merely that it wasnt fully implemented. Thus national security adviser John Bolton is an unrepentant cheerleader for the 2003 Iraq war.

He is also a good exemplar of a second structural explanation. As long as the deal stood, the option of a military strike on Iran was off the table. This too is reminiscent of Iraq, when the UN inspectors could not be given time to complete their job because certifying Iraq to be free of Weapons of Mass Destruction would have removed the excuse for invasion. The first director-general of the Organisation for the Prohibition of Chemical Weapons (OPCW) was the Brazilian diplomat Jos Bustani. In 2002, he tried to convince Iraq to sign the Chemical Weapons Convention so the OPCW could certify it was free of chemical weapons.

AsBustani confirmed a decade later, the US forced his ouster because his effort to place OPCW inspectors in Iraq to certify the absence of chemical weapons would have obstructed the US determination to eliminate Saddam Hussein. The International Labour Organisation tribunal subsequently held Bustanis removal to have been unlawful. The campaign against him was orchestrated by John Bolton, then the US undersecretary of state for arms control and international security. At a tense meeting in his office at The Hague in March 2002,Bustani was told by Bolton: You have 24 hours to leave the organisation, and if you dont comply with this decision by Washington, we have ways to retaliate against you. Pause. We know where your kids live.

On the personal front, Trump has a neuralgic hostility to Iran, loathes any signature Obama policy, is seduced by Saudi Arabia flattery, is bosom buddies with the hardline Israeli PM Benjamin Netanyahu and has inducted fellow-Iran hawks Bolton and Mike Pompeo into his inner circles of top advisers.

Consequences of Withdrawal

Irans pathway to the bomb will be easier and faster with the deal mothballed. The deal had successfully shrink-wrapped Tehrans nuclear weapon ambitions, completely closed off the plutonium pathway to the bomb, severely curtailed the enriched uranium pathway, reduced its medium-enriched uranium stockpile by 98%, restricted future uranium stocks to non-weapon-grade enrichment level and imposed a robust transparency, inspection and consequences regime to ensure compliance. Should Iran resume its journey to the bomb, others in the region could follow suit and create apolynuclear Middle East.

In recent daysFrance,Germanyand theUKhad insisted that the Iran deal was robust and working and the US should comply with its provisions while Iran was doing so.Five hundred MPs from France, Germany and the UKissued an urgent appeal to the US Congress to stay in the deal. On 8 May, literally on the eve of Trumps decision, more than 100former senior European leadersissued an appeal to Trump not to abandon the deal. Relations with Europe, already shaken, they said, would be further damaged by a US failure to meet its commitments when the Iranians are meeting theirs. Failure to waive US nuclear sanctions on Iran would put the United States in material breach of an agreement that has been endorsed by the international community through the UN Security Council and that is important to the security of Europe.

Iran has made it clear that its commitment to the nuclear deal is contingent on the promised sanctions relief materialising. For this to be possible after Trumps decision, Europe will have to confront the US in a damaging trans-Atlantic trade war by insulating European companies engaged in commerce with Iran from secondary US sanctions. The US has past form in asserting extraterritorial jurisdiction of its laws and regulations over non-US companies breaching unilateral US sanctions.

There has also been renewed speculation aboutIsrael and Iran preparing for a military showdownin the contest for political primacy in the region. One potential battleground is Syria. Lebanon, where the pro-Iranian Hezbollah recently won local elections, is another. Trump may have signed up the US to a war option championed by Netanyahuagainst the professional judgment of the Israeli security establishment.

Unilaterally abrogating a multilaterally negotiated and painstakingly crafted deal cannot but be intenselydamaging to US credibilityas a country that honours international agreements. This will affect calculations of all other parties in the ongoing efforts to solve the nuclear crisis on the Korean Peninsula.Obama notedthe absurdity that walking away risks losing a deal that accomplisheswith Iranthe very outcome that we are pursuing with the North Koreans. ARussian official saidTrumps decision calls into doubt the Korean peace process.

Putting these consequences together along with the Paris Pact on climate, Trans-Pacific Partnership and NAFTA on trade the Trump administration is emerging as the biggest threat to nuclear peace and world order as it prioritises might is right as the organising principle of US foreign policy. Daryl Kimball, executive director of the independent Arms Control Association in Washington, attacked Trumps decision to abrogate the Iran deal as anirresponsible act of foreign policy malpractice.

Make America Grate, indeed.

_Ramesh Thakur, a former UN Assistant Secretary-General, is emeritus professor in the Crawford School of Public Policy, Australian National University._In 2017 he was appointed a Fellow of the Australian Institute of International Affairs.