President Trump’s debut speech to the UN (and the subsequent discussion about it) largely centred around his characterisation of North Korean leader Kim Jong-Un as ‘Rocket Man’. But in his wide-ranging speech, Trump touched on a number of different issues from unemployment to the American Constitution – to the very make-up of the UN itself. The bulk of his speech was however saved for the criticism of the new ‘Rogue Regimes’, reminiscent of President George W Bush’s ‘Axis Of Evil’.

It was Trump’s comments on Iran which seemed to rattle most international cages – particularly those in Europe. Britain, France and Germany (along with Russia and China) were heavily involved in getting the Joint Comprehensive Plan of Action (JCPOA) to the table and getting it signed. For many of these nations, it is Iran that presents the most real and present danger in nuclear terms. The fear is that Trump will decertify the Iran nuclear deal; a long-running opposer of the agreement, in his speech he referred to it as “one of the worst and most one-sided transactions the United States has ever entered into…Frankly, that deal is an embarrassment to the United States, and I don’t think you’ve heard the last of it — believe me”.

European diplomats have begun mounting a defence of the nuclear deal for policy ears, and in order to convince Washington that the Iran deal is still in their interests and those of the Middle East. There are a number of benefits that European leaders and diplomats could highlight in order to keep the deal running. For starters, it offers unparalleled access to the Iran nuclear project; rather than guessing the nature of Iran’s programme, the International Atomic Energy Agency is able to conduct intrusive inspections. Though vigilance about the programme from the likes of Trump and Netanyahu is understandable, Secretary of State Rex Tillerson has stated that Iran is keeping it’s programme in check. If this is the case, the US has the chance to use JCPOA to secure further deals instead of starting from scratch.

European leaders may also emphasise the importance of the Iran deal in showing the US is able to contain nuclear problems without implementing regime change – a move which could prove key in achieving a North Korean nuclear deal. Pyongyang is particularly concerned about this; nuclear options serve as Kim’s insurance policy. Having learnt from the example of Colonel Gaddafi, Kim Jong Un is not about to give up his nuclear deal only to be removed later on. As Iran watches US behaviour towards North Korea, the same is happening the other way around. The concern is that walking away from the Iran nuclear deal would undermine Western credibility in staging further deals.

In order for “North Korea to realize that the denuclearization is its only acceptable future”, as the President Trump himself put it, the regime needs to be convinced that scrapping nukes won’t mean an end to their rule. Backing out of the deal would likely hurt the diplomatic legitimacy of the US and its allies – particularly in the DPRK, where there is already so much distrust of the West.

Trump may be merely posturing. He is doubtless aware that Iran is not breaking the conditions of the nuclear deal – but that isn’t the only method the country uses to destabilise the region, or to disrupt the world order. Iran’s behaviour outside of the nuclear deal is cause for concern. The President’s speech reminded the Assembly that “Iranian oil profits go to fund Hezbollah and other terrorists…This wealth, which rightly belongs to Iran’s people, also goes to shore up Bashar al-Assad’s dictatorship, fuel Yemen’s civil war, and undermine peace throughout the entire Middle East.”

It’s clear that Trump wants to talk to Iran about it’s non-nuclear behaviour, and applying pressure to the nuclear deal lets Iran know that the US President is far from won over. The relationship between the two states is still very much oppositional, and Iran utilises a range of techniques to influence events abroad that directly interfere with American policy and threaten American allies. But the nuclear deal doesn’t cover this – so if America does not stick to the deal, it may not be able to strike another.