On the surface, momentum seems to be building toward a further prisoner exchange between Iran and the United States. After two detainee swaps in the past six months, both sides have expressed a desire for more. The Donald Trump administration has made winning the release of US citizens a priority, and the Hassan Rouhani administration called for its own citizens to be allowed to come home. Yet the previous exchanges have not generated any mutual trust.

On June 5, Iran turned over Navy veteran Michael White to US special representative for Iran Brian Hook in Zurich. White had been held in Iran for nearly two years on charges of "insulting the country's top leader” and publicly “posting a private photograph.” The United States then reciprocated by releasing Majid Taheri, an Iranian-American doctor who had been held over a sanctions violation. Science professor Sirous Asgari, who had also been caught up on a sanctions charge, was also allowed to return to Iran, although the United States said his case was unrelated to White’s. These releases followed a similar exchange in December, when Iran freed Princeton graduate student Xiyue Wang, a US citizen who had been held for three years on spying charges, and American authorities freed stem cell scientist Massoud Soleimani, who faced sanctions charges.

The exchanges were a rare foreign policy success for President Donald Trump, who tweeted a note of thanks to Iran after White was freed and called for talks on a “big deal.” On June 16, Hook said he hoped for further prisoner exchanges and talks on all the issues that have bedeviled relations over the past four decades.

The Iranian authorities are not interested. On May 10, cabinet spokesman Ali Rabiei had offered Iran’s readiness for all prisoners to be discussed without any conditions. Contrary to press reports, however, he did not offer to talk directly with the US government on the matter. Ever since the Jan. 3 assassination of Gen. Qasem Soleimani, direct talks with the United States have been off the table. Iran only wants to speak with the Swiss government, which acted as an intermediary in the last two prisoner swaps. Secretary of Iran's Supreme National Security Council Ali Shamkhani dismissed Trump’s call for a ”big deal” and said “no dialogue will be held in the future.”