In the final days before she and Bernie Sanders face the voters of Iowa, Hillary Clinton is leveling the same attack she leveled against Barack Obama. She’s saying that on foreign policy, she’s the only adult in the race.

In their January 17 debate, Sanders declared that, “What we’ve got to do is move as aggressively as we can to normalize relations with Iran. … Can I tell you that we should open an embassy in Tehran tomorrow? No, I don’t think we should. But I think the goal has got to be, as we’ve done with Cuba, to move in warm relations with a very powerful and important country in this world.”

When the debate ended, Team Hillary pounced. Ignoring the second half of Sanders’s statement, the campaign released a video of foreign-policy advisor Jake Sullivan asking, “Normal relations with Iran right now? President Obama doesn’t support that idea. Secretary Clinton doesn’t support that idea, and it’s not at all clear why it is that Senator Sanders is suggesting it. … It’s pretty clear that he just hasn’t thought it through.” Hillary herself added that Sanders’s comments reflect a “fundamental misunderstanding of what it takes to do the patient diplomacy that I have experience in.”

The language echoes Clinton’s attack on Obama after he pledged in a July 2007 debate to meet leaders of Iran, Syria, Venezuela, Cuba, and North Korea without preconditions—a pledge she called “irresponsible and frankly naive.” That attack, like this one, was contrived: Obama wasn’t planning to rush out to meet Iran’s supreme leader any more than Sanders would rush to build an embassy in Tehran. The real debate was about America’s broader relationship with Iran. In 2007, Hillary supported a nuclear deal with Iran but didn’t support thawing the broader U.S.-Iranian cold war. Obama, by contrast, sensed that only if America thawed that cold war would nuclear diplomacy have a chance. That’s part of the reason she voted to label Iran’s Revolutionary Guards a terrorist group and he did not. Clinton wanted to fortify diplomatic efforts by pressuring Iran more effectively than George W. Bush had. Obama wanted to build a relationship with Iran that wasn’t built on pressure alone.

Almost a decade later, the Clinton-Sanders debate is similar. Hillary supports the Iran nuclear deal but insists that it does not herald the beginning of a fundamentally different relationship with the Islamic Republic. In a speech on the agreement last September at the Brookings Institution, she declared that, “This is not the start of some larger diplomatic opening.” In a debate last October she called the Iranians “enemies.”

Sanders, by contrast, sees the nuclear deal as a first step toward “warm relations” between the United States and Iran. He doesn’t articulate the benefits of warmer relations particularly well, but they’re not hard to grasp. When Iran seized British sailors in 2007, it held them for 13 days. After American sailors strayed into Iranian waters earlier this month, Tehran released them after only 15 hours, in large measure because of the goodwill between U.S. Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif, who spoke five times during the crisis.

A warmer relationship between the U.S. and Iran could also improve the chances of a settlement in Syria. Bashar al-Assad’s Sunni opponents cannot remove the Syrian president by force (nor is it clear that America would even want them to). Thus, the best hope for a resolution to Syria’s ghastly civil war is to convince Assad’s patrons, Iran and Russia, that they can ease him out of power in favor of a more legitimate government while retaining some influence in the country. And the better America’s relations are with Iran, the more credible its guarantees about a post-Assad Syria will be.

Granted, that kind of compromise is nowhere in sight, in part because of the militantly anti-Iranian and anti-Shiite policies in vogue among Saudi Arabia’s leaders. But Clinton would bolster Saudi militancy, thus making an agreement in Syria harder. In her speech last fall at Brookings, she pledged to “increase security cooperation with our Gulf allies, including intelligence sharing, military support, and missile defense to ensure they can defend against Iranian aggression.” (Never mind that in Yemen, it’s the Saudis, not the Iranians, who are dropping the bombs.) From her cold-war perspective, Riyadh is America’s ally, Tehran America’s enemy.

Sanders, on the other hand, wants America to use its own rapprochement with Iran to encourage one between Riyadh and Tehran. In his campaign video, Sullivan mocked the Vermont senator for proposing that Iran and Saudi Arabia “join together in a coalition to fight ISIS.” But there are more realistic ways to encourage Saudi-Iranian détente. Last fall, for instance, the Carnegie Endowment for International Peace suggested that the United States push for a new regional security organization for the Persian Gulf—loosely modeled on the Organization for Security and Cooperation in Europe and the Association of Southeast Asian Nations—that includes both Riyadh and Tehran. (Right now, the region’s only security organization, the Gulf Cooperation Council, excludes Iran and Iraq.) Regional-security architecture isn’t sexy, but it’s a way to flesh out the post-cold war vision Sanders is trying to espouse.

Sanders could also note that moving toward normalizing relations with Iran might help that country’s dissidents. There’s no guarantee, of course, that anything America does will stop Iran’s oppression of its own people. But it’s significant that Iran’s hard-liners, who use the supposed American threat to justify their brutality, oppose normalization most vociferously. Iran’s dissidents, by contrast, generally support it. Akbar Ganji, perhaps Iran’s most prominent dissident, told me via email that he backs normalization. In an open letter last August, 74 well-known Iranian critics of the regime wrote that, “Movement toward normalization of Iran’s international relations could make the naming and shaming of the regime’s mistreatment of political dissidents, civil society forces (women in particular) and religious/ethnic minorities more effective.”

Above all, Sanders needs to make it clear that his differences with Hillary Clinton can’t be boiled down to maturity versus inexperience. He is heir to a different foreign-policy tradition. Hillary is comfortable with waging a cold war against Iran because she has a fairly benign view of America’s cold war against the Soviet Union. On her 2014 book tour, she told Jon Stewart that “fighting the Cold War” was part of the “great story” that America must “get back to telling” both to the rest of the world and “to ourselves.” She told Jeffrey Goldberg that in the fight against jihadist terrorism, the United States should learn from the “kind of overarching framework about what we were trying to do that did lead to the defeat of the Soviet Union and the collapse of Communism.”

Sanders, for his part, opposed the Cold War. He not only criticized Ronald Reagan’s policies in Central America, but praised the left-wing Sandinistas whom Reagan sought to overthrow. As a secular democratic socialist, Sanders doesn’t feel the same affinity toward the Islamist adversaries America confronts today. But he remains skeptical that there is a clear moral distinction between U.S. allies like Saudi Arabia and U.S. adversaries like Iran. For Sanders, there is no such thing as a noble cold war.

There are legitimate criticisms of Sanders’s worldview. Just as Clinton has an overly benign view of America’s actions during the Cold War, Sanders clearly had an overly benign view of the communist dictatorships in Cuba and Nicaragua. But in his call to end America’s cold war with Iran, Sanders is challenging the bipartisan foreign-policy consensus in the same way Obama did in 2008. If he leans into that debate, rather than retreating into his economic-policy comfort zone, he’ll become a stronger candidate. And he’ll offer Democrats in Iowa and beyond a foreign-policy debate they deserve.