From JCPOA to War: Steinmeier's Lost Diplomacy

There is a photograph from Vienna, July 14, 2015, that shows Frank-Walter Steinmeier standing among a cluster of diplomats, ties loosened, faces carrying the particular exhaustion of people who have spent too many nights in conference rooms and know, at last, that the talking has produced something. The Iran nuclear deal had been reached. Twenty months of formal negotiation, years of back-channel preparation before that, and Steinmeier, Germany's Foreign Minister, had been at the center of it. He would later describe the agreement as proof that "patience and persistence in diplomacy can succeed even when the conditions are hostile." Eleven years later, the deal is dead, Iran's nuclear facilities are burning, and Steinmeier, now president of Germany, has used the strongest language of his career to call the war that replaced his diplomacy "völkerrechtswidrig" and "vermeidbar." Contrary to international law, and avoidable.

What does it mean to build something with your hands and then watch someone else burn it down?

The Handshake in Vienna

Steinmeier's involvement with the Iran nuclear file did not begin in Vienna. It began during his first term as Foreign Minister, from 2005 to 2009 under Angela Merkel's first coalition, when Germany was already part of the E3/EU+3 format that would eventually become the P5+1 negotiating framework. The format paired the permanent UN Security Council members with Germany and the European Union, giving Berlin an outsized role for a non-nuclear state. When Steinmeier returned to the Foreign Ministry in December 2013, the interim agreement known as the Joint Plan of Action had just been signed in Geneva the month before. The window was narrow but open.

Germany's contribution to the JCPOA talks was specific and underappreciated. While the dramatic breakthroughs happened in the bilateral channel between John Kerry and Mohammad Javad Zarif, Steinmeier's role was structural: holding the E3 together when France threatened to block provisions it considered too lenient, maintaining backchannels to Tehran during periods when the Kerry-Zarif conversation stalled, and hosting preliminary rounds of technical talks. He was not the lead negotiator. But he was, in the language of diplomacy, the honest broker who kept the architecture from collapsing while the principals argued over the details.

The deal itself was a feat of technical compromise. Iran agreed to reduce its operating centrifuges from roughly 19,000 to 6,104 across its facilities, restrict all enrichment to Natanz, limit that enrichment to 3.67 percent, and submit to the most intrusive international inspection regime ever applied to a nuclear program. In exchange, sanctions would be lifted in stages. It was not a peace treaty. It was not a friendship agreement. It was a mechanism, a set of constraints and incentives designed to keep a dangerous situation from becoming a catastrophic one.

Steinmeier believed in mechanisms. His entire career suggested as much.

The Architecture of Belief

There is a particular kind of diplomat who stakes their professional identity on the proposition that talking is always preferable to not talking, and that agreements, however imperfect, are better than the alternative. Steinmeier was that kind of diplomat. His political formation in the SPD, his years as Gerhard Schröder's chief of staff during the Iraq crisis of 2003 when Germany refused to join the American invasion, his patient cultivation of relationships with counterparts who did not share his worldview - all of it pointed in the same direction. Diplomacy was not sentiment for Steinmeier. It was method.

The secret US-Iran channel that preceded the public JCPOA negotiations had been running through Oman since 2012, brokered by Sultan Qaboos. Steinmeier was not part of that backchannel, which was a purely American-Iranian affair. But he was aware of it, and he shaped the European framework that gave the bilateral talks a multilateral home. When Kerry and Zarif needed political cover for compromises that would have been impossible in a bilateral setting alone, the P5+1 format provided it. Germany's seat at that table was Steinmeier's to use, and he used it.

Yet even as the champagne was poured in Vienna, the deal's architects knew what they had not achieved. The JCPOA did not address Iran's ballistic missile program. It did not address Iran's support for proxy forces across the region. It had sunset clauses that would gradually relax restrictions after 10 and 15 years. Wendy Sherman, the American lead negotiator, would later write about the team's awareness that the deal was a beginning, not an end, and that its long-term success depended on a political environment that might not last. She was right about the last part.

Was the deal a genuine path to resolution, or was it a sophisticated way of buying time? The question mattered less in 2015, when time itself seemed like a victory. It matters very much now.

May 8, 2018

The date functions as a hinge in this story. On May 8, 2018, Donald Trump stood in the Diplomatic Reception Room of the White House and announced that the United States was withdrawing from the JCPOA. He called it "a horrible one-sided deal that should have never, ever been made." He signed a presidential memorandum reinstating all US sanctions.

Steinmeier was no longer in a position to respond as a diplomat. He had left the Foreign Ministry the year before, elected to the Bundespräsidency by the Federal Assembly on February 12, 2017, and inaugurated on March 19. The move was conventional, even expected: a senior statesman rewarded with the highest office in the land. But the timing, in retrospect, carries an almost novelistic cruelty. He moved upstairs just as the building caught fire.

The Bundespräsident under the German Basic Law occupies a peculiar constitutional space. Articles 54 through 61 of the Grundgesetz define a role that is representative, ceremonial, and largely symbolic. The president signs laws, receives ambassadors, and delivers speeches on occasions of national significance. Foreign policy is the domain of the chancellor and foreign minister. A president who wades too deeply into policy risks a constitutional crisis. Steinmeier's predecessor, Horst Köhler, resigned in May 2010 after a remark about German military deployments being motivated partly by economic interests was interpreted as a break with political consensus. The office carries weight but not power. Moral authority, not executive authority. It is the kind of distinction that matters very little until it matters completely.

And so Steinmeier watched. He watched as the European signatories scrambled to save the deal without the Americans.

The Slow Collapse

What followed Trump's withdrawal was not an immediate collapse but a slow bleeding. The Europeans launched INSTEX, the Instrument in Support of Trade Exchanges, in January 2019, a financial mechanism designed to allow European companies to trade with Iran outside the reach of American secondary sanctions. It was ingenious on paper. In practice, it processed a single transaction of medical goods. No European company of any significance was willing to risk American retaliation for the sake of the Iran deal. INSTEX was a monument to good intentions and insufficient leverage.

Iran, for its part, began exceeding the JCPOA's limits in calculated increments from July 2019 onward. Each breach was announced publicly, framed as a reversible response to American bad faith. Enrichment rose to 4.5 percent, then 20 percent, then 60 percent by April 2021. The IAEA's access was progressively restricted. By the time enrichment reportedly crossed the weapons-grade threshold of 90 percent, the original deal was not just dead but decomposed.

Between the breaches, attempts at revival sputtered and failed. The Oman backchannel that had birthed the original talks was revived in 2019 and 2020, but Sultan Qaboos died in January 2020 and his successor, while continuing Oman's mediating tradition, lacked the personal relationships that had made the first channel possible. The Swiss channel, through which Washington and Tehran communicate as a function of Switzerland's role as protecting power for US interests in Iran, carried messages but produced no breakthroughs. The EU's E3 triggered the JCPOA dispute resolution mechanism in January 2020, a step that, under the agreement's terms, could eventually lead to the reimposition of UN sanctions. It was meant as leverage. Tehran read it as betrayal.

The killing of Qasem Soleimani by a US drone strike in Baghdad on January 3, 2020, was the moment when the language of diplomacy became visibly inadequate to the reality on the ground. Whatever space had existed for negotiation contracted sharply. Each subsequent event narrowed it further. Did anyone in this slow-motion escalation have the power to stop it? Or does each actor's rationality, taken individually, produce collective irrationality?

The Diplomat in the Palace

During these years, Steinmeier was not silent, but he was careful. A Bundespräsident speaks in registers that are measured, allusive, deniable. He gave speeches about the value of multilateralism, about Europe's responsibility in a fragmenting world order, about the lessons of German history for the use of force. Those who knew the Iran file could read the subtext. The general public heard platitudes. That is the nature of the office.

What changed in March 2026 was not the content but the volume. Steinmeier's statement that the Iran war was "völkerrechtswidrig" and "vermeidbar" abandoned the usual presidential circumlocution. It was direct, it was specific, and it was devastating in its implications. A president who helped build the framework that was supposed to prevent this war was now saying, on the record, that the war was both illegal and unnecessary.

The political reaction was immediate and predictable. Union politicians accused him of overstepping his constitutional role. The AfD, in a symmetry that made nearly everyone uncomfortable, agreed with the president. The SPD was caught between loyalty to its most prominent member and the demands of coalition politics. But the political noise obscured something more fundamental. This was not merely a constitutional controversy about the boundaries of presidential speech. It was the sound of a man accounting for his own legacy.

Is that courage? Is it grief? Does the distinction matter?

The Weight of "Vermeidbar"

The word sits at the center of everything Steinmeier said, and it is the word that carries the most personal freight. "Vermeidbar." Avoidable. He is not simply offering a legal assessment or a policy critique. He is saying: the thing I built could have prevented this. The framework I invested years of my life in was the alternative to what is happening now. It was destroyed, and what has followed is what I warned it would be.

The question of whether he is right is not simple. Had the JCPOA survived in its original form, Iran's enrichment would have remained capped at 3.67 percent under IAEA monitoring for at least another decade. The pathway to a weapon would have been stretched to at least a year's breakout time, providing ample warning for diplomatic or other responses. That much is technically defensible.

But the critics of the JCPOA always argued that it addressed only the nuclear dimension while leaving Iran's broader behavior untouched. The ballistic missile program continued. The Islamic Revolutionary Guard Corps maintained and expanded its network of regional proxies. The sunset clauses meant that even the nuclear restrictions would eventually expire. The deal, in this reading, was not a solution but a deferral, and the crisis it deferred would have arrived eventually, possibly in worse conditions.

Steinmeier knew these arguments. He heard them from Benjamin Netanyahu, who called the deal a "stunning historic mistake" at a press conference in Jerusalem the day it was announced. He heard them from skeptics within his own diplomatic corps. He heard them from the Americans who preceded and followed Kerry. He chose to build the deal anyway, because the alternative was worse. Now the alternative has arrived, and it is indeed worse. Does that vindicate him? Or does it merely confirm what everyone already feared: that the deal was a temporary reprieve from an intractable problem?

There is no clean answer. The honest observation is that Steinmeier built the best available mechanism with the tools and partners he had, and that the mechanism was dismantled by a successor who neither understood it nor cared to. Whether a better mechanism could have been built, or whether the fundamental dynamics made war inevitable regardless, is a question that historians will debate long after the current crisis has ended.

Other Architects, Other Ruins

Steinmeier is not the first person to watch a peace framework they constructed collapse into violence. The history of diplomacy is littered with agreements that did not hold. Neville Chamberlain's name became synonymous with naivete after Munich 1938, a comparison so powerful that it has distorted foreign policy thinking for nearly a century. Every diplomat who argues for negotiation with an adversary is eventually asked: are you not just another Chamberlain? The question is dishonest, because it assumes that the only alternative to appeasement is confrontation, when in practice most diplomacy occupies a vast middle ground. But it is a question that Steinmeier will face now, if he has not already.

The Oslo Accords of 1993 offer a different kind of parallel. Yitzhak Rabin staked his political career and ultimately his life on the belief that a negotiated peace with the Palestinians was possible. He was assassinated for it. The framework he built did not collapse all at once but eroded over decades, undermined by maximalists on both sides and by the sheer difficulty of implementing compromise under fire. The architects of Oslo were not naive. They were overtaken by forces larger than themselves.

The Good Friday Agreement of 1998 is the rare case where a diplomatic framework survived against the odds, though it remains under periodic strain. What made it durable was not the brilliance of its drafters but the sustained political commitment of multiple generations of leaders who chose, again and again, to defend the structure rather than abandon it. The JCPOA never received that sustained commitment. Its American architect walked away. Its European defenders lacked the power to compensate. Its Iranian participants found reasons to exceed its limits. And the German who helped build it was promoted to a position from which he could only observe.

What separates the frameworks that hold from those that shatter? It is not the quality of the draftsmanship. It is the willingness of those who follow to maintain what was built. Steinmeier built well enough. Those who came after did not maintain.

What Remains

Frank-Walter Steinmeier is 70 years old. His second and final presidential term will end in 2027. The defining achievement of his diplomatic career lies in rubble, and the war he spent years trying to prevent is underway. His statement in March 2026 may be the most consequential act of his presidency, not because it will change the course of the war, but because it forces Germany to confront a question it would rather avoid. If the president who negotiated the alternative says the war was avoidable, what does that say about the choices that led here?

He cannot rebuild the JCPOA from Schloss Bellevue. He cannot convene a negotiation from a ceremonial office. What he can do, and what he has done, is name what happened. The deal existed. It worked. It was destroyed. The war came. These are not opinions. They are a sequence.

Whether naming matters is a question for a time after the bombs have stopped. For now, there is a man in a palace who once sat in hotel lobbies making something work, and who has chosen, at the end of his career, to say that the destruction of that work was a choice, not a fate. It is the kind of statement that changes nothing in the short term and everything in the long one, or nothing at all.

The difference between those outcomes depends on who is listening.