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On a November night in 2013, Barack Obama delivered a statement about an interim nuclear deal that had just been reached, freezing Iran’s program in place. When he was done, I walked with him back to the entrance of his residence, watched by the stoic portraits of former presidents. “Congratulations,” I said. “You just made sure that we won’t have a war with Iran during your presidency.”

“That’s probably true,” he said, considering the question. “But I want to make sure that the next president doesn’t have to go to war either.”

Obama was referring to the need to reach a comprehensive deal that rolled back Iran’s nuclear program. It would take almost two years of painstaking negotiations to get there, but the Joint Comprehensive Plan of Action (JCPOA) accomplished that objective. Under the terms of the JCPOA, Iran destroyed the core of a reactor that could have produced plutonium for a bomb; removed two-thirds of its centrifuges, the machines that can enrich uranium for a bomb; shipped 98 percent of its stockpile of enriched uranium (enough for 10 bombs) out of the country; and submitted to the most comprehensive international inspections regime ever put into place to monitor a nuclear program.

These achievements are worth revisiting, because any hope of saving the Iran deal likely died with the killing of Qassem Soleimani. Indeed, it’s no surprise that the Iranian government has indicated that it will no longer abide by the limits on its nuclear program imposed by the JCPOA.

How did we get here? The debate over the Iran deal was among the most acrimonious of the Obama years. Throughout 2015, congressional Republicans stridently opposed it. Israel, the United Arab Emirates, and Saudi Arabia worked to marshal opposition. Think tanks churned out alarmist reports about the JCPOA. Tens of millions of dollars were spent by outside groups such as the American Israel Public Affairs Committee and United Against Nuclear Iran urging Congress to kill the deal. To prevent that legislation from passing, we worked frenetically to muster 41 Democratic Senate votes to uphold a filibuster. Indeed, the fact that it was far easier for George W. Bush to take the United States into an unnecessary war in Iraq than it was for Barack Obama to secure a nuclear deal to avoid one with Iran says something deeply strange and alarming about our country and its politics.

As soon as he began his run for the presidency, Donald Trump anointed himself the most strident of the JCPOA’s opponents, calling it “the worst deal ever negotiated.” It is likely, of course, that Trump couldn’t even describe the Iran deal’s terms. He failed to articulate a different set of nuclear restrictions, or to offer his views on the nature of centrifuges that Iran should be allowed to operate, or the research and development it should be permitted to perform. Trump simply wanted to destroy anything that Obama built and to satiate right-wing supporters who had their own reasons for opposing the JCPOA. What Trump could do is lie about the Iran deal, and he did so relentlessly.

Upon becoming president, Trump encountered an inconvenient truth: The Iran deal was working. Trump’s own intelligence community and military leadership confirmed that Iran was complying with the JCPOA’s terms; his own secretary of defense argued publicly that staying in the JCPOA was in America’s interest; and all the other parties to the deal—the European Union, the United Kingdom, France, Germany, Russia, and China—opposed Trump’s instinct to pull out. After Trump refused to certify that Iran was complying with the JCPOA (even though it was), even Republicans in Congress quietly refused to reimpose sanctions. And after Trump demanded a better deal, French President Emmanuel Macron offered him the opportunity to pursue one through negotiation, provided that the JCPOA stayed in place. Despite all this evidence and all these efforts, Trump withdrew from the Iran deal in May of 2018 and started reimposing sanctions.

Few recent presidential decisions have been proved to be so spectacularly wrong in such a short period of time.

Trump said that in withdrawing from the JCPOA, he would be in a stronger position to stop Iran’s provocations across the Middle East. The opposite has proved to be the case. Iran has already resumed aspects of its nuclear program that were restricted under the JCPOA. And over the past year alone, Iran or its proxies have shot down a U.S. drone, harassed and seized oil tankers, bombed Saudi oil infrastructure, killed unarmed protesters, and resumed rocket attacks against U.S. interests in Iraq. During the implementation of the Iran deal, by contrast, there wasn’t a single such rocket attack from a Shia militia. Trump initiated the escalatory cycle that led us to this extraordinarily dangerous moment.

It is ironic that the killing of Qassem Soleimani could put the final nail in the coffin of the Iran deal. In the Obama White House, we assessed that Soleimani opposed the JCPOA, and that he led a hard-line flank that viewed the Iranian foreign minister who conducted the negotiations with suspicion. This view was often mocked by Iran-deal opponents, who declared that there was no distinction between hard-liners and more moderate Iranian officials. Indeed, U.S. hawks regularly foreclose opportunities for diplomacy by wrongly seeing the government of any adversary as a monolith. But now, in the wake of Soleimani’s assassination, that debate is largely moot: As mourners flood the streets, all of Iran’s leaders are consolidating around a harder line, vowing to chase the United States out of the region.

We have already seen the consequences of this latest escalation in Trump’s “maximum pressure” campaign come into focus. Iraqi leaders are demanding that we leave their country, after Americans sacrificed thousands of lives and spent more than $1 trillion there; new restrictions are inhibiting the fight against ISIS; Iran is casting off the remaining limits on its nuclear program. In the months and years to come, we should expect renewed attacks against U.S. interests—and Americans—from Iran and its proxies. In contrast to the international unity that enabled the achievement of the JCPOA, Trump’s abandonment of it has alienated the United States from our closest allies. And in his other signature foreign-policy initiative—negotiations with North Korea—Kim Jong Un is pushing forward with his own nuclear and missile programs, perhaps having drawn the lesson that you cannot trust the United States to keep a nuclear deal.

In response, Trump and his chief lieutenant on Iran—Secretary of State Mike Pompeo—have sought to deflect blame to the JCPOA. While blaming the Iran deal for the consequences of Trump pulling out of the Iran deal is absurd, this argument should come as no surprise. Trump’s Iran policy was formulated in opposition to Obama, not with an eye toward actual governing. His is a worldview that relies on false charges, hyperbolic rhetoric, and assertions of strength as an end in itself, and not as a means to achieving something. At a Cabinet meeting last year, Trump sat at the table with a Game of Thrones–style poster that read “Sanctions are coming,” as if it were all just a movie, and not real life.

By contrast, the Iran deal was designed to address reality, and discharge the responsibilities of governing. Like any such effort, it was imperfect, and left all parties dissatisfied. For the Iranians, it was flawed because it didn’t lift all sanctions; it did, however, offer relief from certain sanctions and the prospect of further relief if Iran continued to comply. For us, it was flawed because the JCPOA’s most effective restrictions on the Iranian nuclear program expired in 10 or 15 years—but that was 10 or 15 more years of assurance than having no deal in place, and further negotiations that built upon the JCPOA were always an available option. Finally, the JCPOA didn’t stop Iran’s ballistic-missile program or its support for terror in the Middle East; however, the JCPOA did ensure that a regime that has ballistic missiles and supports terror was verifiably prohibited from obtaining a nuclear weapon. That was the whole point. You don’t make nuclear deals like that with your friends.

Indeed, imagine how the current crisis would feel if Iran already had nuclear weapons.

Governing isn’t about making demands on other countries that will never be achieved just because they sound good back in Washington. And the presidency certainly isn’t a movie. When “sanctions are coming,” real people get hurt and terrible things can happen in the real world. One legacy of the JCPOA is that it demonstrates the utility of a different approach.

As Trump confronts the consequences of a crisis of his own creation, he can thank Obama for the fact that Iran doesn’t yet have the means to produce a nuclear weapon. He can thank Obama for the fact that Iran’s nuclear program is set back from where it was in 2015. He can thank Obama for the inspections regime that has functioned effectively. By contrast, the result of Trump’s policy—designed for Fox News sets and campaign rallies—has been a more hard-line Iranian politics, an Iranian adversary that has stepped up its provocations, and a newly unconstrained Iranian nuclear program.

Barack Obama did achieve a deal good enough to prevent his successor from having to go to war with Iran. But now, despite all that work, a de facto state of war exists between the United States and Iran. To keep his promise to kill an achievement of Obama’s, Donald Trump has been willing to break his promise to get us out of wars in the Middle East. In doing so, he has tragically proved Obama right: The choice all along was between the Iran deal or an unconstrained Iranian nuclear program and some form of war.

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