After far too long, Iran has agreed to release a number of Americans who had been held in its terrible prisons. The five—Washington Post reporter Jason Rezaian, pastor and missionary Saeed Abedini, former U.S. Marine Amir Hekmati and two others whose detention had not been publicly reported—are now on their way out of Iran. Their first stop will be at a U.S. military hospital in Germany—likely a necessary measure, as those held in Iran’s carcels are often denied adequate food and medical care. They will not be the first American casualties of Iranian action to enter that hospital—a number of U.S. military personnel wounded by Iranian-armed militias during the occupation of Iraq would have been treated there in the past.

Tried in secret on trumped-up or unsubstantiated charges, libeled in the Iranian hardline press, denied consular access and even proper legal representation, the five appear to deserve Iran’s apologies. Yet the world of international affairs is rough, and they had the misfortune of becoming pawns in a greater struggle.

In return for the prisoner release, the United States agreed to cease actions against a number of Iranians convicted or accused of sanctions violations. Many of them seem to have been involved in Iran’s efforts to procure sensitive electronics, materials and technologies needed by Iran’s nuclear and defense programs. Another was trying to smuggle American weapons to Iran. Such actions clearly harm American national security, and the majority justly received places in federal prison. Yet even here, there are ambiguities—sanctions law, like so many other areas of federal administrative law, has confusing and constantly shifting red lines, with severe penalties for those who step beyond wherever those lines happen to be at the moment. A few of the Iranian prisoners may have received harsher punishments than they deserved. One, for example, appears to have willfully broken the law, but a law that changed three weeks after he pled guilty. Others may not have realized that they were breaking the law.

Even so, there were clearly nefarious characters among the Iranians, and the Iranians have presented no evidence of any equivalent offense by the Americans. Presidential candidate Marco Rubio was well within bounds in questioning the merits of swapping guilty Iranians for apparently innocent Americans. “This tells us everything we need to know about the Iranian regime—that they take people hostage in order to gain concessions,” said Rubio. “And the fact that they can get away with it with this administration I think has created an incentive for more governments to do this around the world.” The Obama administration, in turn, should explain why this is not the case.

This is of acute importance, as the Iranians appear not to have released Siamak Namazi, an Iranian-American businessman apparently picked up by the Revolutionary Guards some months ago. Who will the Iranians ask in return for him? And who will keep his case in the spotlight here? Jason Rezaian had journalists advocating for him. Saeed Abedini had Christian groups. Amir Hekmati had Marines. With most business transactions between the United States and Iran still illegal even after sanctions relief, it is hard to imagine the Chamber of Commerce or other business groups banging on doors in Congress on his behalf. The same is true of Rezaian’s colleagues in the press. Iran presently holds a number of journalists in its prisons, journalists not fortunate enough to have dual citizenship. Newspapers on both ends of the political spectrum in Iran face harassment and closure. Who will speak for them? Iran’s move, in this regard, appears prudent: Tehran still has at least one American hostage, yet one who lacks the constituencies to raise awareness and add a “yes, but” to every news story about how nice things are in the Islamic Republic. The price to Iran of holding prisoners may have fallen somewhat, even as the incentives to take them may be rising.

The prisoner swap included another troubling dynamic. Iran’s ballistic missile tests last fall broke a UN Security Council resolution. The United States was due to impose sanctions in response, yet at the last minute announced they’d be delayed without offering a clear explanation. We now know that the Iranian foreign minister Mohammad Javad Zarif warned his American counterpart John Kerry that the imposition of sanctions would scuttle the prisoner talks. He was probably right—the internal dynamics of Iran put prisoners, especially sensitive ones, beyond the control of the foreign minister. An internal negotiation was certainly going on in parallel to the external one. Give and take like this is certainly a normal part of diplomacy; given the limited practical benefit of putting a few new strictures on Iran’s already heavily sanctioned missile program and the real harm of a breakdown in the prisoner swap talks, delaying sanctions was hardly madness. Even so, it is concerning that the Iranians were able to establish a linkage between an issue of international security and an issue of human rights, and were able to win (small) concessions on security in return for ceasing its violations of several Americans’ human rights. The incentives this could create are alarming; we will see in the coming years whether Iran intends to take advantage. At least one professional diplomat involved in the talks faulted the administration for its approach, telling the Huffington Post’s Jessica Schulberg that “we’ve been so shallow, spineless, naive, gullible and stupid.” (The diplomat told Schulberg he’d quit the State Department largely out of frustration with the Obama administration’s Iran approach.)

However, tradeoffs like these are also a product of the narrowness of U.S.-Iranian relations: when one side doesn’t like what the other is doing in one area, but lacks leverage in that area, it has few other areas in which it can respond. Even with sanctions coming off, this narrowness isn’t going to change too much, especially since many of the areas where the relationship will be getting deeper are mandated in the nuclear deal, limiting flexibility. A more multilateral approach, with Washington coordinating more with European states that have better relations with Iran, may be useful in reshaping dangerous incentive structures.

In spite of these many concerns, the successful prisoner swap and this week’s release of American sailors who had inadvertently entered Iranian waters remain signs of several positive dynamics within the U.S.-Iranian relationship and the Iranian system. Hardline actors are being restrained or are willing to restrain themselves for now from the most aggressive measures to sabotage an opening. The two sides are, in spite of Iranian supreme leader Ali Khamenei’s purported prohibition on direct talks, able to communicate and come to agreement; in the case of the sailors, this certainly helped contain what could have otherwise been an explosive international crisis. In the case of the released prisoners, it relieves the suffering of several particular Americans. Hopefully Iran’s successful bargain won’t lead, however, to new hostages and, someday, new concessions.

John Allen Gay, an associate managing editor at The National Interest, is coauthor of War with Iran: Political, Military, and Economic Consequences (Rowman and Littlefield, 2013). He tweets at @JohnAllenGay.

Image: Flickr/yeowatzup.