President Trump’s decision to abandon the Iran nuclear deal ranks as his most reckless policy move yet. It is also his biggest triumph so far in his continuing bid to reverse or shatter every one of his nemesis-predecessor’s major accomplishments, regardless of the consequences.

And there will be consequences. Some may turn out to be rather narrow, while others could have a global impact. Some may emerge as the direct result of US actions, while others will depend on how other governments and nongovernmental actors respond. Life will almost certainly become more difficult for ordinary Iranians, who are still coping with crippling US-imposed economic sanctions unrelated to the nuclear deal.

The worst outcome, of course, would be a full-scale regional or even global war. Such a conflict could even lead to the unthinkable: the use of nuclear weapons by one of several nuclear-weapons states. (That list, we should remember, does not include Iran.) And while war is certainly not inevitable, we need to recognize that there are many ways in which one could come about. One of the most commonly discussed could result from an Iranian decision to respond in kind to Trump’s violation of the deal, known as the Joint Comprehensive Plan of Action (JCPOA).

But first it must be emphasized that virtually all intelligence and nonproliferation agencies in the world—from the International Atomic Energy Agency (IAEA), the UN’s nuclear watchdog, to all 16 US intelligence agencies, the intelligence communities of all the signatories to the deal, and even top Israeli military officials—agree (grudgingly or not) that Iran has complied with the JCPOA. Trump’s claims all had to do with what he asserted were the insufficiencies of the JCPOA’s terms, not that Iran had violated those terms.

Trump’s withdrawal from the deal, and his re-imposition of the nuclear-related sanctions that the JCPOA required the United States to lift, constitutes the only violation so far. And so far, Iran has made clear that it intends to stick to the terms of the deal, based on the fact that the other six signatories—Britain, China, France, Germany, Russia, and the EU—are still on board. But if forces within the Iranian government that were always skeptical of the deal use the US withdrawal to gain the upper hand and get Tehran to withdraw from it, the consequences could be incredibly dangerous, since not only the Trump regime in Washington but Israel and Saudi Arabia too would almost certainly respond by calling for war. What is preventing such a move so far is the Iranian government’s maturity and commitment to diplomacy.

Even if Tehran doesn’t abandon the JCPOA, Washington could launch a regime-change war against Iran, perhaps claiming that without a “better deal,” war would be the only way to keep Americans safe. We’ve heard that one before: Trump’s new national-security adviser, John Bolton, wasn’t just a cheerleader for confrontation with Iraq during the Bush administration; he played a major role in undermining diplomatic alternatives and setting the conditions for the disastrous 2003 US invasion. Bolton has long urged a US military attack on Iran and has long supported the opposition cult known as the Mojahedin-e Khalq, or MEK, which he thinks should replace the Iranian government. That group was removed from the US list of foreign terrorist organizations only in 2012 after a major lobbying campaign that involved the MEK paying former US officials millions of dollars in “speaker fees.” One of those officials, recently appointed Trump lawyer and former New York City mayor Rudy Giuliani, told a gathering of MEK supporters a couple of days before Trump’s announcement that the president was committed to regime change.

Of course, a Trump “commitment” says very little about what the notoriously mercurial president might actually do. Even with Bolton and hawkish new Secretary of State Mike Pompeo leading the White House bomb-Iran contingent, there’s no guarantee that Trump will move toward war. That’s why we need a concerted public, media, and congressionally focused campaign to raise the political price in the coming elections for Trump allies and others who may believe a bomb-Iran approach will help them win votes.

There’s another potential war threat, possibly without any mention of regime change, which is also familiar from the Iraq precedent—a breakdown in the inspections regime. As noted, Iran has so far made clear that it has no intention of violating its obligations under the JCPOA, which include allowing intrusive inspections. But if at some point in the future Tehran decides to stop cooperating with the IAEA inspectors, how long will it take before Trump and his war minions turn up the rhetorical heat on the alleged dangers posed by an “uninspected” Iran? Might we see a repeat of an Iraq-style “there are no inspectors!” or “the inspectors are being conned!” leading to a direct US attack? That’s why it’s so important to keep reminding the press, the public, and Congress that Iran remains in compliance.

Beyond the various US initiatives that could threaten war, Israel continues its direct provocations, including military attacks against Iranian targets in Syria, one of them reportedly just hours after Trump announced he was abandoning the JCPOA. The Israeli moves are even more threatening to Iran because of the growing and increasingly public alliance between Israel and Saudi Arabia, a US-backed partnership designed precisely to build a regional front against Iran. The Saudi war against Yemen started in 2015 partly as a result of Saudi Arabia’s long-standing competition with Iran—based on Riyadh’s view that Tehran’s quite marginal support for Yemen’s Houthi rebels, who had seized power in Sanaa, provided a new justification for a direct assault on Iran’s allies.

Israeli Prime Minister Benjamin Netanyahu, who has long pushed for a direct attack on Iran, played a major role in persuading Trump to abandon the JCPOA. Right now, Netanyahu is close to being indicted on a wide range of corruption charges, so his ratcheting up of anti-Iran fear and hysteria is a useful diversion from his growing domestic political problems. (Sending hundreds of Israeli sharpshooters and other troops to the Gaza fence to kill and maim scores of nonviolent Palestinian protesters and injure thousands more, however popular, isn’t quite enough for a get-out-of-jail-free card.) Iran’s privileging of diplomacy over war could be reversed if the Israeli provocations, especially in Syria, escalate so dramatically that Iranian public opinion demands greater military reaction.

Another set of threats includes the weakening of international efforts toward nuclear disarmament, nonproliferation, and, ultimately, abolition of nuclear weapons (that last goal is rarely taken up by diplomats, but it should be). Trump’s abandonment of the Iran deal is a major setback for those efforts, though not because Washington was a leading force in working for nuclear disarmament—the United States has been in violation of Article VI of the Nuclear Non-Proliferation Treaty’s requirement of moving toward complete nuclear disarmament since it was signed half a century ago. It’s a setback because every failure of nuclear diplomacy increases the danger of non-diplomatic action. And non-diplomatic action, as we know, has always failed.

We can see how this might play out in the Korea nuclear crisis: Trump’s decision to withdraw from the JCPOA was based partly on the specious claim that he could get a “better deal,” which increases the pressure on him to come up with a “better” deal—meaning a more pro-US deal—with North Korea than Obama and the other signatories were able to negotiate with Iran. And that’s just not going to happen. So diplomatic progress in the Korea crisis has just become more difficult. It’s become more difficult for another reason, too: North Korea may decide that, because of Washington’s abandonment of the JCPOA, there’s no reason to sign any agreement at all, because the United States can’t be trusted to keep its word.

And then we have the threats that Trump’s move poses to US diplomacy, already shredded from more than a year of massive cuts in the staff and budget of the State Department, disdain for diplomacy throughout the administration, and the privileging of war-supporters over diplomats in all positions of power. Washington’s credibility with its allies, already as low as at any point in recent history, is tanking even further. The failure of the intense efforts by European leaders, in particular, to prevent Trump’s abandonment of the JCPOA has only heightened the serious division between Washington and the most influential European countries, including those leaders (of France and Britain) most eager to keep the transatlantic partnership viable. Trump’s closest European cheerleaders are now the right-wing leaders of Eastern and Central European countries such as Hungary and Poland, along with the rising right-wing politicians increasingly vying for power in Western Europe.

So far, the European signers of the JCPOA, as well as China and Russia, have made it clear they intend to continue abiding by the terms of the agreement. That means they intend to continue trading with Iran. The crucial question now is how aggressively Washington intends to punish, through secondary sanctions, those European countries and businesses that insist on continuing to trade with Iran—and how aggressively Europe will resist such secondary sanctions. How much impact would Washington’s renewed sanctions have on Iran if not only European countries but China, Russia, India, and other non-European countries stick to their promise to continue trading with Iran, braving US threats to interfere with their banks? It’s possible that, with Washington out of the picture, a new level of diplomatic engagement with Iran might open up—perhaps even stronger initiatives toward making the Middle East a nuclear-weapons-free zone, something Iran has long supported but was always stymied by Israel’s US-protected nuclear arsenal.

Trump’s abandonment of the JCPOA has made Washington’s isolation more obvious than ever, directly exposing the United States status as a rogue nation. Nations that have historically been close US allies—in much of Europe, South Korea, and beyond—are pulling away, and Washington, particularly the Trump White House, increasingly looks to Israel and the Arab monarchies of the Gulf, most of all Saudi Arabia, as its key partners, with warm and fuzzy relations expanding with authoritarian regimes in the Philippines, Egypt, Turkey, and elsewhere.

The consequence of this shrinking of US power over international diplomacy is still unclear. Certainly diminishing the domination of the US empire is a good thing for much of the world. It remains uncertain, however, who will fill the vacuum, and where global diplomatic leadership might come from. Freed from Washington’s control, a new level of internationalism might become possible, including on issues the United States often blocked, such as diplomatic rather than military resolutions to many conflicts, progress toward nuclear abolition, a global approach to the climate crisis, refugee protection, and more. Certainly there are key leaders who may be able to take on such an expanded global role, and some of them are close to winning power (Britain’s Jeremy Corbyn comes to mind, as does Mexico’s Andrés Manuel López Obrador). Civil society can help on this front; social movements around the world must demand new diplomatic initiatives that do not come from the United States.

Maybe, with enough global collaboration between social movements and politicians, this reckless US threat against Iran will have a positive outcome after all. But we have to act now to make it happen. Complacency is not an option.