Republican critics of the deal have lambasted President Barack Obama for ignoring their fate, while the administration counters that the agreement was focused only on Iran's nuclear program and that adding other topics to the agenda, as morally compelling as they may be, would have further complicated the negotiations.
Iranian President Hassan Rouhani surprised many last Sunday when he offered a way forward:
a prisoner exchange between both countries. The four Americans in Iran could, he suggested, be swapped for the 19 Iranians held in U.S. prisons for violating Iran sanctions law.
His comments leave the ball in America's court. How should the Obama administration respond?
For a start, it's important to acknowledge the moral absurdity of drawing any parallels between the two sets of prisoners. The Americans in Iran are being held on bogus charges by an Iranian judiciary dominated by hard-liners and lacking transparency.
The real reasons behind the detentions of Jason Rezaian, Amir Hekmati and Saeed Abedini are unclear, but it seems likely that internal rivalries over Iranian policy played a role. (Tehran denies even holding Robert Levinson, who went missing more than eight years ago). In contrast, the Iranians in American jails have broken U.S. law and have been jailed after open trials that met international standards of due process.
This appears to be part of a history of tactical hostage-taking on the part of Iran, dating back to the 1979 Iranian Revolution and the capture of the U.S. Embassy in Tehran, through the 1980s, when pro-Iranian groups in Lebanon held American citizens hostage, and into the 1990s and 2000s when Iranian-Americans traveling to Iran would be arrested and charged with espionage.
All of this suggests that hostage-taking has been a persistent tool of Iranian statecraft that is unlikely to change anytime soon.
Still, it's also important to remember that a swap would likely not be the first quid pro quo between the two sides. In 2009, according to the Wall Street Journal, the Sultan of Oman secretly provided a list of names to the White House of prisoners that Tehran wanted released from U.S. jails.
The communications allegedly made clear that a positive response from Washington would help create a more conducive atmosphere for discussing Iran's nuclear program. It is worth noting that the release of Sarah Shourd, an American hiker arrested on the Iraq border in 2009, came after the release after Shahrzad Mir Gholikan, an Iranian national convicted of smuggling night vision equipment. (The U.S. government, it should be pointed out, has officially denied exchanging prisoners, and most of the Iranian prisoners who have returned home have served their full sentences.)
Of course, taking up President Rouhani's offer of a prisoner swap in this case is risky for the Obama administration, not least because it would likely encourage other rogue states and other groups to seize American citizens in exchange for U.S. concessions. And there's also the damage to the integrity of our legal system if convicted felons are released from jail before serving their full time.
Iranian hard-liners, meanwhile, would celebrate, claiming that they had forced the "Great Satan" to capitulate and that arresting the U.S. detainees was the right thing to do. And Republicans at home would no doubt seize upon any prisoner exchange as evidence the president had caved to terrorists.
But none of these risks negate the compelling humanitarian reality that without a prisoner exchange, American citizens in Iran will be left in Evin Prison. With little leverage to secure their release, they will be condemned to years of hardship, deprived of their basic human rights and of a meaningful existence.
All this means there are only two options available to the Obama administration -- stand up for your principles and resist Iran's thuggish demands, or compromise and secure the release of American hostages. As the administration wrestles with this issue, it is important not to lose sight of our broader strategic engagement with Iran, and how the nuclear agreement has created new opportunities that should not be squandered.
One path forward could be to set principle aside, to a degree, and revisit the cases of the 19 Iranians. Those who have served most of their sentence, and who have been convicted of lesser crimes that didn't significantly affect U.S. national security, could be penciled in for early release and exchanged for the four Americans held in Tehran.
After his brother was imprisoned in Iran, Alex Fattal, the brother of one of the American hikers, wrote in an insightful essay, the "Prisoner's Dilemma": "Barack Obama's administration should double down on diplomacy and reach out to the Iranian regime," he said, noting that even if diplomacy does not "precipitate a breakthrough (which it almost certainly will not) and Iran continues to lean on the rhetorical crutch of anti-Americanism (which it almost certainly will), the redoubled outreach will entrench the political fissures in the Iranian establishment."
"Those on the neoconservative end of the spectrum in the Beltway would do well to consider this simple truth: Engagement is more controversial in Tehran than in Washington."
Fattal's advice is still relevant today. Hard-liners in Iran desire nothing more than an end to Iran-U.S. dialogue, and hawkish rhetoric and threats of war merely play into their hands and weaken the more moderate and reformist voices among Iran's ruling elite seeking engagement with the West.
In fact, as I write, news of a purported handshake between Iranian Foreign Minister Mohammad Javad Zarif and President Obama at the United Nations this week has reached Tehran, prompting howls of outrage from Iranian conservatives. This suggests that engagement is a path we should continue to follow and encourage, because it opens at least a small door for political change in Iran.
Securing a prisoner exchange would be another significant step on this path. And it might even yield some unintended benefits down the road.