By Aaron David Miller

Wall Street Journal "Washington Wire",  Sept. 9, 2015

The Iran nuclear agreement looks all but certain to proceed through the U.S. Congress in the coming days. Whether you love the deal, hate it, or are still undecided, the inconvenient truth is that the durability of the agreement and its benefits for the U.S. depend almost entirely on the moderation of Iran’s regime and its behavior in the region.

In defending the accord, President Barack Obama has asserted that regardless of whether Iran becomes more moderate, Tehran without a nuke is better than a Tehran that has the bomb. It’s hard to argue with this.

But this reasoning fails to account for three factors that will continue to make Iran a formidable adversary. And in some ways, the agreement–regardless of restrictions on Iran’s nuclear program–could make the regime even more dangerous.

It is virtually impossible to separate Iran’s nuclear weapons aspirations from the nature of the regime, its ambitions in the region, or its view of the United States. Iran’s desire to become a nuclear weapons threshold state or maintain the option to weaponize at some point was driven by its desire to preserve its highly ideological and authoritarian character. Iranian leaders are looking to protect the 1979 revolution and create a hedge against regime change by hostile powers–principally the U.S. and key Sunni Arab states–that they believe are seeking to encircle or overthrow the government in Tehran. Iran is driven by a sense of insecurity and entitlement when it comes to regional standing. And Henry Kissinger was right years ago that as long as Iran remains a cause rather than a nation, it will not abandon its nuclear weapons pretensions.

Iran doesn’t (yet) have a nuke, and U.S. intelligence assessments are that Tehran has yet to make a decision about weaponizing. Right now, the threat to the U.S. and its allies isn’t what’s in the agreement but actions that fall outside it–namely, Iran’s ambitions in the region. Iran isn’t a superpower; its allies (embattled Syrian leader Bashar al-Assad, Hezbollah, Houthi rebels in Yemen, Shiite militias in Iraq) are pretty weak tea and expensive to maintain. But compared with the weaker foes they face in Iraq and their influence among Shiite Muslims, these proxies can do major damage in terms of undermining political reconciliation and stability and ensuring that Iran remains the most important regional actor in Iraq, Lebanon, and Syria–the areas Tehran really cares about. Now, consider that in exchange for time-limited restrictions on a nuke the Iranian government doesn’t yet have, it will get billions in sanctions relief. The exact amount is less important than the capacity those funds give Tehran to bolster its surrogates.

Now, consider this irony: Iran’s primary partner in the nuclear deal is the U.S.–a country that Tehran has consistently used to mobilize hard-line elements within Iran and to maintain its revolutionary character. Since the terms of the deal were announced in July, Iran’s supreme leader, Ayatollah Ali Khamenei, has made numerous statements criticizing Washington and President Obama. He continues to refer to the U.S. as the Great Satan. He said again Wednesday that there would be no negotiations with the U.S. outside the nuclear issue and opined that in 25 years the Zionist entity–Israel–would not exist. The regime that purged Iran of U.S. influence in 1979 has no intention of letting Washington back in. For the regime, the nuclear deal was a means of reinforcing the revolution by getting international sanctions on Iran’s economy lifted, attracting foreign investment, and satisfying popular desires for better quality of life. Next year Iran is scheduled to hold elections for parliament and the council responsible for choosing the next supreme leader. Let’s see how Iranian moderates and reformers fare.

The bottom line is that President Obama was wrong. Ultimately, success of the nuclear deal depends on significant changes in Iran’s regime at home and its policies abroad. Without such changes, Iran will not give up its option to weaponize. And this agreement will leave Tehran with the nuclear infrastructure to pursue that option should it so choose. Absent some moderation in these ambitions, the next U.S. president–Democrat or Republican–might decide that negative Iranian actions–whether within or outside the parameters of the accord–would be grounds to walk away from the deal’s provisions.

So the big questions are: Can Iran change? Will the nuclear agreement hasten that moderation at home or abroad? A large swath of Iran’s population is young, and many are pro-Western and eager for both better lives and more connections to the outside world. Will foreign investment and influence loosen things and satisfy the public’s thirst for greater freedom? Highly authoritarian and ideological states–China, the former Soviet Union, Vietnam–have proven adept at opening up while maintaining tight control. Right now, that outcome looks likely for Iran too.

Aaron David Miller is a vice president at the Woodrow Wilson Center for Scholars and most recently the author of “The End of Greatness: Why America Can’t Have (and Doesn’t Want) Another Great President.” He is on Twitter: @AaronDMiller2.