MADRID – With President Donald Trump’s announcement that the United States will begin reimposing sanctions against Iran, the short, strange life of the 2015 Iran nuclear deal – formally known as the Joint Comprehensive Plan of Action – has entered a new and dangerous phase.

Trump believes that, by withdrawing from the JCPOA, he can pressure Iran to agree to a new, more comprehensive deal that would cover not just the country’s nuclear program, but also its ballistic missile tests, provocative regional behavior, and human-rights violations. But, as America’s partners and allies have noted, this is a highly risky gambit – one that contradicts the underlying logic of the deal.

The decision to withdraw from the JCPOA, despite Iranian compliance with all of its provisions, is likely to make addressing Iran’s nuclear program more difficult, not least because it will strengthen the position of the country’s hardliners.

Trump claims that the JCPOA was a failure from the start, owing to the myriad non-nuclear issues that it neglected. Indeed, he called it "one of the worst and most one-sided transactions” into which the US has ever entered.

The JCPOA’s supporters have inadvertently reinforced this reading. French President Emmanuel Macron, for example, recently advocated bolstering the agreement with complementary deals covering other areas. In conceding the premise that the deal was somehow incomplete, supporters and detractors alike set it up to fail.

The truth is that the JCPOA was never supposed to be a one-off "transaction.” Instead, it was conceived as the first step in a long negotiation process. The "comprehensive” in its official title refers to the lifting of nuclear-related sanctions and the verification measures to ensure compliance. It did not indicate that the deal amounted to a comprehensive solution to all of the international community’s disagreements with Iran.

The point was to take a particularly knotty and urgent issue – Iran’s growing nuclear-enrichment capacity – off the table for a period of time, to allow for progress in other areas. Had all of the issues been negotiated at once, it is far from clear that a deal could have been reached at all, much less in a timely manner. After all, previous attempts to negotiate with Iran – notably under President Bill Clinton’s administration – failed precisely because they sought to secure too much. There were just too many potential spoilers.

The JCPOA was not simply a precedent for further agreements; it actually demanded them. The so-called sunset clauses that stipulate expiration dates for various restrictions imposed on Iran’s nuclear program – clauses that attracted so much derision from Trump and other opponents of the deal – were vital, because they necessitated further negotiation.

Thanks to the lifting of sanctions under the JCPOA, that negotiation would take place against a background of steadily improving economic conditions, which would persuade the Iranian public of the tangible benefits of a moderate and cooperative approach. This would strengthen the government’s resolve to strike deals on other controversial issues – precisely the opposite of the likely effect of Trump’s unilateral withdrawal from the JCPOA.

The risks implied by Trump’s worldview are particularly acute in today’s fast-changing world. On one hand, power has shifted and become more diffuse, while the mismanagement – and misrepresentation – of globalisation has created further uncertainty.

It is now starkly apparent that we can no longer rely exclusively on the top-down Western-dominated structures that have underpinned the rules-based world order for the last 70 years. Though we should not dispense with those structures, much less the rules-based order, we must develop new, complementary instruments to foster cohesion and create the conditions for effective cooperation.

The 2015 Paris climate agreement – from which Trump withdrew the US last year – is a case in point. Nobody believes that the soft and voluntary commitments that signatories have made will be enough to limit global warming to "well below” 2° Celsius (3.6º Fahrenheit) above pre-industrial levels. Nonetheless, the deal is valuable: it spurs action now, while acting as a platform for further commitments later.

The writer is a member of the Spanish Council of State, a visiting lecturer at Georgetown University, and a member of the World Economic Forum’s Global Agenda Council on the United States.

Copyright: Project Syndicate.