On Tuesday, President Donald Trump announced the US’s intention to withdraw from the Joint Comprehensive Plan of Action, the July 2015 agreement between a US-led group of six world powers and Iran aimed at constraining the Islamic Republic’s nuclear program. “The agreement was so poorly negotiated that even if Iran fully complies, the regime can still be on the verge of a nuclear breakout in just a short period of time,” Trump declared. Moments later, he signed an order that ended the executive waivers needed to implement the nuclear deal, essential reimposing all US sanctions on Iran within 180 days. It’s unclear whether the agreement can survive without American participation, or what form the international effort to prevent Iran from obtaining a nuclear weapon will take now that Washington is dramatically changing course.

The JCPOA was perhaps was the biggest priority of former president Barack Obama’s second term in office. Unsurprisingly, the former president is not a fan of Trump’s latest move. “Walking away from the JCPOA turns our back on America’s closest allies, and an agreement that our country’s leading diplomats, scientists, and intelligence professionals negotiated,” the former president stated in a lengthy Facebook post that outlined reasons for keeping the deal—Obama claimed that “Iran is complying with the JCPOA,” and that “the JCPOA does not expire.”

John Kerry, Obama’s Secretary of State, was unsparing. “Today’s announcement weakens America’s security, breaks America’s word, isolates us from our European allies, puts Israel at greater risk, empowers Iran’s hardliners, and reduces our global leverage to address Iran’s misbehavior, while damaging the ability of future administrations to make international agreements,” he wrote. “No rhetoric is required. The facts speak for themselves.”

Iranian foreign minister Javad Zarif signaled that Iran will not immediately pull out of the agreement, and that his government might even stay in the deal in spite of the impending re-imposition of all US sanctions. He tweeted that he plans to spearhead a diplomatic effort to examine whether remaining JCPOA participants can ensure its full benefits for Iran. “Outcome,” he wrote, “will determine our response.” Theresa May, Angela Merkel, and Emmanuel Macron, the leaders of the United Kingdom, Germany, and France, respectively, released a joint statement restating their commitment to the deal—and suggesting that Iran was still bound to the agreement because of a vote in the UN Security Council regardless of the US’s position. “We recall that the JCPOA was unanimously endorsed by the UN Security Council in resolution 2231. This resolution remains the binding international legal framework for the resolution of the dispute about the Iranian nuclear programme.”

A few foreign governments, however, have announced support for the US move. Predictably, Israeli prime minister Benjamin Netanyahu commended Trump for his move to “reject the disastrous nuclear deal with the terrorist regime in Teheran.” Saudi Arabia, the United Arab Emirates, and Bahrain voiced their approval, too.

Republican members of Congress, on their end, backed the president’s move. “The Iran deal has always been terrible,” Nebraska senator Ben Sasse opined, attacking the deal for being implemented as an executive agreement carried out at the sole discretion of the president, rather than a Senate-approved treaty. “American foreign policy makes lasting progress when it’s led by the president, approved by Congress, and presented honestly to the American people.” In contrast, Vermont Senator Bernie Sanders released an over six-minute video message arguing that the decision to leave the deal had brought the US closer to war. “Real American leadership and real American power isn’t show by an ability to blow things up, but by an ability to bring parties together, to forge international consensus around shared problems, and then to mobilize that consensus to address those problems. That is what this agreement did. Unfortunately, president Trump put us on a very different, more dangerous path.”