Heinz Peter-Bager / Reuters

If the U.S. and Iran conclude a nuclear deal next week, the Islamic Republic stands to gain billions of dollars in eventual sanctions relief. But money isn’t the most important reason the Iranian leadership may be set to shake hands with its historic enemy after 18 months of negotiations.

“One of the most important reasons Iran is signing this deal, in my opinion ... is not actually sanctions,” said Vali Nasr, the dean of Johns Hopkins University’s School of Advanced International Studies. “It’s ISIS. There is actually support for this deal within the Revolutionary Guards in Iran, because their day job is right now fighting ISIS, and they need the United States, particularly in Iraq, on the right side of that fight.”

Nasr made his remarks at the Aspen Ideas Festival, during a panel on the Iran nuclear deal in which the word “paradox” came up several times in reference to the relationship between the United States and Iran.

Karim Sadjadpour of the Carnegie Endowment for International Peace invoked Henry Kissinger to describe that motif in the U.S.-Iran relationship since the 1979 Iranian Revolution. In his 2002 book Does America Need a Foreign Policy?, Kissinger wrote that “there are few nations in the world with which the United States has less reason to quarrel or more compatible interests than Iran.” Sadjadpour rattled off a list of common enemies spanning decades: the Soviet Union, Saddam Hussein, al-Qaeda, and now ISIS. But the moments of what he called “tactical cooperation” have not managed to erode the “strategic enmity.” Iran, Sadjadpour said, needs to decide if it’s a nation or a movement opposed to the U.S. and Israel.

Iran’s fear of ISIS is itself a paradox insofar as Iran helped create the conditions for the group’s rise through its support of both the regimes of Bashar al-Assad in Syria and Nouri al-Maliki in Iraq. “Iran is both the arsonist and the fire brigade in the Middle East,” Sadjadpour said. And as far as U.S. support for the Iran-backed militias confronting ISIS in Iraq is concerned, Sadjadpour said that “it’s an open question whether partnering with Shia radicals to kill Sunni radicals creates more Sunni radicals than it eliminates.”

Given the costs of this kind of tactical cooperation with Iran, and the endurance of strategic enmity regardless, does it make sense for the U.S. to keep trying to engage the country? More than Kissinger, it’s a 1980s-era Saturday Night Live cast member who may have best explained the U.S. relationship with Iran—in explaining his own diet. “I’m not a vegetarian because I love animals,” Sadjadpour quoted A. Whitney Brown as saying. “I’m a vegetarian because I hate plants.”

“Our engagement with Iran, dialoguing with Iran, shouldn’t be considered a gift to the regime itself because we like them,” he continued. “In fact these hard-line elements in Iran really don’t want to be engaged; they thrive in isolation.”  

Meanwhile, though, it’s not clear how much the Iranian regime is thriving in the chaos of the Middle East. In January, after Iranian-backed Houthi rebels staged a coup in Yemen, The Economist wrote that: “Iran can claim, with only a pinch of hubris, to run three Arab capitals: Baghdad, Damascus, and Beirut. This week it may have added a fourth.”

But what kind of hegemon is Iran with capitals like these? Sadjadpour pointed out that Iran exercises influence over four extremely weak states, three of which are in the throes of civil war. Sunni powers in the region may look at spreading Iranian influence in the Middle East with alarm. But Iranian leaders, Nasr said, see “sort of a concerted Sunni effort to push them out” of their spheres of influences—“the Turks to the north, the Saudis to the south, and ISIS in the middle. … They’re all basically trying to take away, you know, Damascus from Tehran, Beirut from Tehran, Baghdad from Tehran.” Not to mention the Yemeni capital of Sanaa, which Saudi Arabia has been trying to wrest back from the Houthis through a months-long bombing campaign in Yemen.

The upshot is that Iran may not be as threatening to the United States as its nuclear program and regional influence make it appear. Sadjadpour maintained that the Iranian regime can be deterred precisely because it wants to stay in power, and that in any case nuclear weapons wouldn’t protect it from the real threat the U.S. poses: America’s cultural influence on a highly educated populace that wants to engage with the world.

The disconnect between the Iranian regime and its people is yet another paradox, and it may be the most important one for U.S.-Iran relations over the long term. “Hard-line elements” in Iran’s leadership, Sadjadpour said, “have sought to emulate North Korea, while the society they rule seeks to emulate South Korea. [Iranians] want to be integrated, they want to be economically prosperous. And I think if this deal happens, and it helps to reintegrate Iran politically, and in the global economy, that will empower those more moderate forces in Iran … and potentially weaken some of these hard-line forces that have really thrived in isolation, the same way Kim Jong Un and Fidel Castro have thrived in isolation.”

“The Iranian state is homicidal, not suicidal,” he said. “I think certainly let’s contain Iran, let’s check Iran’s influence in the region ... but let’s not aggrandize Iran to a global superpower, which it certainly isn’t.”

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