The Maximum Pressure Campaign: How Trump Isolated Iran

The Islamic Republic of Iran has consistently been a destabilising force in Middle Eastern geopolitics. With Donald Trump resuming the presidency in January 2025, his administration will have to confront how to credibly restore deterrence against the regime in Tehran. While the President-elect instinctually understands the art of deterrence – his recent threat of there being ‘all hell to pay’ to Hamas over the hostages held in Gaza being a case in point – reverting to the maximum pressure campaign in the early phases of his second term could create the right conditions for the United States to restore general deterrence against Iran. In this article, I examine what made the maximum pressure campaign so effective in isolating Iran and argue that the first step to restoring general deterrence with Iran is to once again implement the maximum pressure campaign.

Indeed, the mercurial nature of the regime has manifested itself repeatedly throughout the last four and a half decades. During the Bush and Obama years, the Islamic Republic’s habit of flouting the international Treaty on the Non-Proliferation of Nuclear Weapons (NPT) began, first in 2002, and later again in 2003. And from 2006 to 2012, Iran refused to halt its uranium enrichment program, breaching six United Nations Security Council resolutions. Bush, admittedly, had no concrete strategy to counter Iran upon entering office. As part of the global war on terror, however, Bush did name Iran as part of the axis of evil, along with Saddam Hussein’s Iraq and Kim Jong Il’s North Korea, accusing Iran of being a state sponsor of terrorism, an accusation that has since proven to be accurate.

President Obama, on the other hand, did make restraining Iran’s ambitions to become a nuclear power a foreign policy priority. And in July 2015, along with government representatives from the UK, France, Germany, Russia, China and a delegate from the European Union, the United States and Iran signed the Joint Comprehensive Plan of Action (JCPOA). Key terms of the JCPOA obliged Iran to reduce its uranium enrichment capacity for a period of ten years; conduct all its enrichment related activities at a single facility at Natanz; maintain uranium stockpiles under 300 kg and up to maximum of 3.7 percent for fifteen years; keep its stockpile of heavy water under 130 metric tonnes; and allow IAEA to ensure compliance with these terms through regular, long-term inspections. In exchange for Iranian compliance, overseas assets amounting to $100 billion would be unfrozen and certain economic sanctions that would enable Iran to trade oil on the international markets and have access to global financial systems would be lifted.

When Donald Trump came into office in 2017, his intention was to withdraw from the JCPOA. Obama’s strategy of exercising nuclear diplomacy collapsed partly because of Trump’s disdain for the deal, but not solely. The initial deal itself possessed inherent shortcomings, failing to address key aspects that directly threatened core US interests in the region, such as stability and the security of close allies. Namely, Iran’s ICBM programme and Iran’s state sponsor of terrorism were not issues the JCPOA confronted. Furthermore, evidence shows that Iran had no intention of honouring the JCPOA in the first place, having breached the JCPOA’s terms before Trump even came into office, on two separate occasions.

In February and November of 2016, the IAEA confirmed that Iran had exceeded the limit for heavy water production. In relation to Iran, the notion that US foreign policy in the Middle East always risks collapsing resonates, particularly when liberal institutionalists such as Barack Obama and Joe Biden seek to find multilateral solutions to immutable problems, such as the ideology of a regime. The Iranian regime’s ideological character can make it seem entirely unamenable to reason. It is actively engaged in efforts to eradicate the Jewish state, and its hegemonic aspirations in the region are based on the pursuit of religious primacy over its Sunni Muslim neighbours.

Trump’s realist approach was more suited to dealing with a rogue actor such as Iran, and his maximum pressure campaign produced desirable strategic outcomes. Firstly, imposing heavy sanctions on Iran incapacitated the regime from being able to access precious financial resources, and stifled Iran’s economy. This exposed the fact that the regime’s deeply held aspirations came at the expense of the Iranian people’s wellbeing. Whilst ordinary Iranians suffer, the regime chooses to allocate state funds toward funding terrorism abroad, abdicating from its responsibility of providing basic public services, managing its natural resources, and assisting the public with domestic crises. As of 2018, a third of Iranian youths were unemployed; and fuel and water shortages were recurrent. The further the Iranian regime’s aims diverged from the needs of the Iranian people, the greater the possibility for change.

Secondly, Trump’s assassination of Quds Force general Qassem Soleimani, in January 2020, sent a signal to Iran that the failure to abandon their pernicious activities could come at a heavy cost, and that so long as he was in office, nothing—not least of all military force—would be off the table.  This approach was in line with a core principle of Trump’s foreign policy doctrine: the idea that peace can only be obtained through strength.

Since the Biden administration came into power, Iran has not only intensified its belligerence in the Middle East, by employing barrages of ballistic missile strikes against Israel, but by also furthering its subversive operations regionally and in the West. Because the regime in Tehran’s core foreign policy mission involves exporting its extreme Shia revolutionary ideology, and will employ any means to achieve this aim, denying the regime the ability to do this is fundamental to deterring its nefarious activities.

By isolating Iran, the Trump administration would deny Iran the strategic incentive of attacking US regional allies and facilitate the restoration of a credible deterrence strategy. Simultaneous to reconstituting the maximum pressure approach, Trump will have to restore deterrence by establishing escalation dominance with Iran, demonstrating US conventional military capabilities to devastating effect. As Robert Peters stated: ‘In many cases, escalation, or the threat of escalation, is required or desirable to achieve the desired objectives.  In fact, deterrence by cost imposition inherently requires the withheld threat of escalation and is not credible without a willingness to do so.’ Reminding Iran of US nuclear capabilities too, however, by signalling that the US actively maintains the option to employ nuclear force against Iranian vital interests, is certainly an escalatory threat Trump could persuasively leverage against Tehran.

Ultimately, however, the long-term deterrence mission against Iran will have to transcend the employment of force and include other domains to ensure that Iran never becomes a nuclear weapons state, that it ceases to conduct subversive operations in asymmetric domains in the West, that it ceases to attack Israel, and that it is also deterred from destabilising other US allies and partners in the region in the long term. By combining his instinctive penchant for issuing sufficiently credible threats with an approach to deterrence that reflects today’s security landscape, Trump could bolster US regional deterrence effectiveness. But before enhancing deterrence, Trump will first need to restore it. The first step toward restoring deterrence with Iran is to isolate the regime. The maximum pressure campaign has successfully managed to do that in the past and will do so again if implemented.

Alex Alfirraz Scheers holds a diploma in Politics and History from the Open University, a bachelor’s degree in War Studies and History from King’s College London, and a master's degree in National Security Studies from King’s College London. He has held research positions at the Henry Jackson Society and the International Centre for the Study of Radicalisation, and his articles have been published in the Diplomat, Times of Israel, RealClearDefense, and the Royal United Services Institute.