Leonhard Foeger / Reuters

The Trump administration’s withdrawal from the Joint Comprehensive Plan of Action—the nuclear deal with Iran—and its renewal of sanctions, the rise of Iran’s provocations in the Gulf and Iran’s enrichment of uranium have together reignited the debate over how best to meet the multiple threats posed by Iran. Once again, the proponents of using military force against Iran are squaring off against the advocates of diplomacy. Though the debate is primarily an internal American dispute, the people it will most profoundly affect are the Iranians, Arabs, and Israelis who will live with the consequences of any decision made by the United States.

The majority of Israelis and Arabs would agree that negotiations are preferable to war with Iran, but only if they put an end to Iran’s nuclear ambitions, its support for terror and construction of intercontinental missiles, and its campaign to dominate or destroy other states in the region. As a former Israeli official, I have a deep interest in avoiding a conflict likely to result in massive civilian casualties on both sides. As a historian who opposed America’s invasion of Iraq, even testifying against it in Congress, I know the hazards of war making in the Middle East. But diplomacy will be fruitless, and war eventually guaranteed, if the illusions surrounding the JCPOA persist.

The first of these falsehoods is that Iran could somehow be bought. In return for sanctions relief, followed by tens of billions of dollars in international contracts, the Islamic Republic, the assumption went, would abandon its commitment to extending Shiite hegemony. The notion that diplomacy alone could transform Iran into a constructive regional power—oddly promulgated by the champions of multiculturalism—shocked Israelis and Arabs. Our dismay was swiftly vindicated as Iran harnessed the legitimacy and proceeds of the JCPOA to increase its financing of terror and hasten the spread of its influence across much of the Middle East. This expansion has already triggered deadly conflicts with Iranian-backed forces in Yemen and Gaza, with far larger conflagrations looming with Hezbollah in Lebanon and in Syria, where Iran facilitated the government’s massacre of hundreds of thousands of civilians and its displacement of millions more. The violence in the region is certain to escalate in the coming years, even if Iran appears to comply with the JCPOA.

This gives rise to the second myth: that the nuclear deal must be maintained because Iran is honoring its terms. This was precisely the fear of Arabs and Israelis—not that Iran would violate the agreement, but rather that Iran would uphold it. And why not? The deal enriched Iran financially while recognizing its right to enrich uranium. In fact, no such right exists—certainly not for a country that lied about its nuclear program for decades. Why wouldn’t Iran hold to a treaty that preserved its nuclear infrastructure, enabled it to develop more advanced centrifuges, and ignored its construction of intercontinental ballistic missiles capable of carrying nuclear warheads? The agreement does not require Iran to come clean on its previous military nuclear efforts, to sever its ties with international terror, or to stop threatening neighboring states. It does not open all Iranian nuclear sites to unrestricted inspection. It even contains “sunset clauses” that will lift most of the minimal limits on Iran’s enrichment capacities within a decade. The ease with which Iran is now expanding uranium enrichment proves the flimsiness of the deal, even as it illustrates the reason Iran’s rulers are so keen on keeping it.

The last and most pernicious myth is that the only alternative to the JCPOA is war. It reflects understandable war-weariness in the United States from the ongoing conflicts in Iraq and Afghanistan, and fears of further Middle Eastern entanglements. Those emotions enabled the Obama administration to move from the position that no deal is better than a bad deal to insisting that any deal is better than no deal; from asserting that all options are on the table to claiming that there is no military solution, and then to promoting a policy of either diplomacy or war.

That last dichotomy was false at the time of the JCPOA’s signing, and it remains so today. The threat of U.S. military action against Iran, though never taken seriously in the Middle East, proved effective in swaying American public opinion. But a massive invasion and occupation was never the model for confronting Iran. The precedents, rather, were the surgical missile and aerial strikes launched by President Ronald Reagan against Libya and by President Bill Clinton in Sudan. As Israel’s ambassador in Washington in 2012, I often heard then–Israeli Defense Minister—now peace-camp leader—Ehud Barak assure American policy makers that the bombing of Iranian nuclear sites would last no longer than one or two days, and involve minimal risk to U.S. forces. “What are you afraid of?” he asked.

The answer, according to JCPOA proponents, is terror. Striking or even sanctioning Iran, the Nobel Peace Prize winners Shirin Ebadi and Jody Williams recently wrote in The New York Times, “will only lead to greater ‘malign behavior’ on the part of Iran in Iraq, Yemen and Syria.” In other words, Iran must be bribed to act less monstrously. This is the same Iran that has launched cyberattacks against the United States, made millions smuggling drugs into America, and threatened international oil shipments in the Gulf. This is the same Iran that sought to assassinate me—when I served as the Israeli ambassador—and my Saudi counterpart in Washington, D.C. And it is the same Iran that killed hundreds of U.S. troops in Lebanon and Iraq, and that—after the signing of the JCPOA—captured and humiliated U.S. Navy sailors. The question is not what threats Iran will pose if its aggression is resisted, but rather the destruction the country will cause if it is not.

In theory, negotiations offer the best way forward. They could resolve Europe’s contradictory policy of backing a nuclear deal that helps fund the ethnic cleansing of Syria and bankrolls the Assad regime that Europe sanctions. For Israelis and Arabs, especially, talks with Iran stand to replace a deal concluded duplicitously behind our backs with an existential enemy, in disregard for the tenets of Shiite Islam, and with no thought whatsoever for the future security of the Middle East. And diplomacy is better than a conflict in which we, and not the West, are likely to be Iran’s first targets.

But if diplomacy is to succeed, it must be backed by punishing sanctions and a credible military threat. Indeed, the more credible the threat, the less chance it will have to be used or that the United States will be dragged into any number of Iranian-fueled conflicts. Only when confronted with the choice between pursuing their aggression and risking economic ruin, threatening global security and facing armed action, will Iranian rulers forfeit their nuclear program and their dreams of empire. Only then will our region, and ultimately the world, be safer.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.