US President Donald Trump has traded military threats and counter-threats with Iranian President Hassan Rouhani in an exchange alarmingly similar to the fiery war of words with Kim Jong-un last year.

These threats of military force are strategic rather than merely random outbursts by an unpredictable and thin-skinned President.

We have seen Mr Trump’s game plan before in his approach to Pyongyang: aim high, exert “maximum pressure” on your opponent using all necessary means to expand points of leverage and force a deal on terms most favourable to America.

US aims to force weakened Iran back into talks

After the US withdrawal from the Iran deal in May, Iran is now seeing similar elements of a “maximum pressure” strategy being applied toward it.

The Trump Administration seeks the complete, verifiable and total denuclearisation of Iran rather than the partial roll-back and temporary freeze of the latter’s nuclear program agreed under the deal.

The recent boast by the head of Iran’s atomic energy organisation, Ali Akbar Salehi, that Iran could restore uranium enrichment to 20 per cent within four months merely emphasises the poor bargain struck by the Iran deal: It did not eliminate but merely delayed Iran’s acquisition of a nuclear weapon, in return for the elimination of sanctions.

The second major aim of the maximum pressure campaign is to cut off Iran’s access to sources of outside funds, to curb its interventionist behaviour and force it back to the negotiating table but in a weak bargaining position.

Since the removal of sanctions and return of frozen funds, Iran has increased its support for Hezbollah, Hamas, Yemen’s Houthis, Iraqi Shia militias, and Syria’s Bashar al-Assad, working directly against both US interests and those of its allies in Saudi Arabia, the UAE and Israel.

The US will reinstate all sanctions removed by the Iran deal by November 4, including virtually all trade and investment by US firms with Iran and the sanctions on Iranian oil exports which had crippled the Iranian economy.

Threats of regime change worked on NK

The question then becomes whether this strategy will work. In the case of North Korea, the maximum pressure campaign did force Pyongyang to reconsider the costs and benefits of continuing on the path to developing a credible nuclear deterrent.

Mr Trump’s threats of war, while seemingly implausible, introduced an element of risk that the US would force regime change, the very thing North Korea’s nuclear program seeks to avoid.

China too was finally persuaded to agree and enforce unprecedented sanctions on the regime to avoid the real prospect of war on the peninsula, the influx of refugees, collapse of the North Korean state, and the reunification of the two Koreas on terms unfavourable to it without direct military intervention itself.

Mr Trump should be given credit for getting North Korea to the Singapore Summit, but his reputation as a “deal-maker” has been seriously dented by unconvincing outcomes.

The summit was a public relations coup for Kim Jong-un, elevating him on the world stage, in return for the promise of “denuclearisation” within some unspecified timeframe, with no benchmarks attached.

Mr Trump’s train-wreck post-summit media conference also undermined the credibility of his previous threats to use military force against the regime, with his complaints about the costs of defending his South Korean ally, and acknowledgement of the vast loss of life that would occur, all suggesting that such threats were merely bluff.

Trump may be bluffing, but Iran has no nukes

In the case of Iran, Tehran may well believe that Mr Trump here too is bluffing. However, the crucial difference is that Iran has not yet developed a nuclear weapon.

In a conventional war, the US and its allies would have the decisive advantage. Even so, the reinstitution of economic sanctions against Iran, particularly oil sanctions, is enough to give the Mullahs pause.

After all, between 2012 and 2016, the period of steep international oil and financial sanctions, Iran’s GDP growth consistently fell into negative territory including -6.6 per cent in 2012, and -5.6 per cent in January 2016.

Many will argue that the EU’s continued support for the Iran deal and refusal to reinstate sanctions against Iran will mean that a return to an old strategy will not work this time. The EU is making attempts to salvage the deal, offering a package of economic measures to entice Iran to stick with it in May.

Iran, however, says the package is inadequate.

The EU is also talking tough and has begun the process of activating a “blocking statute” which bans EU companies and courts from enforcing US sanctions.

These measures, however, are likely to have little effect in derailing the “maximum pressure” campaign. There are few global companies and states that can bear the loss of access to US dollar transactions and the US financial system.

The US has already refused to give a waiver from US sanctions to EU companies transacting with Iran, showing a determination to bear the displeasure of its allies, something underscored at the recent NATO summit. In reality, the Iran deal cannot be salvaged.

Iran still reeling from ‘green revolution’

Mr Trump’s approach is also more likely to succeed in the context of Iran’s existing domestic turmoil.

Iran’s leadership has already faced the most serious public protests since the “green revolution” in 2009. In late December 2017 and early January 2018, protests erupted in more than 100 Iranian cities in response to mounting unemployment and inflation, a currency collapse against the US dollar and a general economic downturn. The return of the US sanctions campaign will severely compound these economic woes and fuel further internal unrest.

In short, the “maximum pressure” campaign is likely to bring Tehran back to the table, but in a much-weakened position.

The US has been in this position before in 2015, with the Obama administration squandering its leverage and accepting a sub-optimal nuclear deal.

Let’s hope that Mr Trump has learnt from the Singapore summit, and will not play his hand so badly this time.