The most recent case is that of Xiyue Wang, a Chinese-born American citizen and doctoral candidate at Princeton University who was arrested on suspicion of sending classified information to the US while conducting historical research in Iran. His accusers indicated that he had photocopied thousands of pages of library documents, but Princeton representatives objected that this is standard procedure for graduate researchers.

In this sense, Wang’s story is reminiscent of that of Jason Rezaian, the Washington Post journalist who was arrested in 2015 and sentenced to an unspecified prison term before being released in January 2016 as part of a prisoner exchange that coincided with the implementation of the Iran nuclear agreement, or Joint Comprehensive Plan of Action. Rezaian’s advocates, including his brother Ali, said that his conviction had been based in large part on the fact that he had shared information with “hostile nations,” mainly by reading or watching Iranian news and then discussing it with friends and colleagues in the US and Europe.

Rezaian was released alongside three other prisoners in last year’s exchange. But with the public acknowledgement of Wang’s arrest it is now clear that all four of those apparent political prisoners, or hostages, have been replaced. The other three who are known to currently be in detention are US-Iranian dual citizens Siamak Namazi and his father Baquer, and the Lebanese information technology and US permanent resident Nizar Zakka.

The arrests and convictions of these men are generally viewed in a context similar to the earlier arrests. That is to say, they are indicative of an ongoing crackdown on persons with ties to the West, as well as on Iranian citizens with alleged pro-Western views and attitudes. Al Jazeera’s report on the upheld convictions calls renewed attention to the fact that Iranian hardliners have been noticeably anxious about “infiltration” in the wake of Iran’s relative opening to Western business in the wake of sanctions relief under the nuclear agreement.

According to Voice of America News, “an unknown number of Iranians holding European passports are also believed in custody in Iran,” including citizens of the United Kingdom, France, and Austria. But whereas those countries’ governments appear to still be supporting the expansion of relations with the Islamic Republic, the US has sharply pulled back from such reengagement since last January’s inauguration of President Donald Trump. VOA News points out that Trump responded to Wang’s July sentencing by saying he was “prepared to impose new and serious consequences” on Tehran unless all wrongfully imprisoned American citizens were released.

Nevertheless, Tehran publicly acknowledged the rejection of each of the four appeals on Sunday, in what could be seen as a deliberate display of defiance against the US. Various reports detailing the appeals point out that their rejection comes at a time of generally increased tensions between Tehran and Washington. Al Jazeera notes that Iranian officials have essentially parroted Trump’s ultimatum, accusing the US of unlawfully keeping Iranian citizens in prison.

Iranian Foreign Minister Mohammad Javad Zarif asserted that Iranians were serving sentences in the US for “sanction violations that are not applicable today … for bogus and purely political reasons.” Although nuclear-related sanctions were suspended under the JCPOA, all those who are serving sentences on that basis today were arrested and convicted while the sanctions were still in effect. Additionally, last year’s prisoner exchange involved the Obama White House releasing or dropping charges against 21 Iranians, with most of the relevant charges having to do with violation of the newly-suspended sanctions.

The Foreign Ministry’s attempt to portray Iran as the victim in the current situation is reminiscent of the back-and-forth between Iranian officials and representatives of the Trump administration since the beginning of the year, with each side accusing the other of being in violation of the “spirit” of the nuclear agreement. President Trump has predicted that he will declare Iran out of compliance the next time he is required to report to Congress on the issue, in October. While this is not primarily based on clear violations of the agreement’s own terms, Iran’s rhetorical reaction may strengthen the White House’s case.

In recent weeks, Iranian officials including President Hassan Rouhani have suggested that the Islamic Republic could ramp up its nuclear enrichment activities to unprecedented levels within days of the JCPOA’s cancellation. When Rouhani first took office in 2013, he was embraced as a relative moderate by some Western officials. He also attempted to strengthen that reputation during his campaign for reelection in May of this year, even though no domestic reforms had been observed during his first term.

As well as highlighting the persistence of Iran’s hardline foreign policy under the Rouhani government, the affirmation of the US citizens’ prison sentences is arguably indicative of the continued growth of pressure on the Iranian people as a whole. Sunday’s public announcement of the rejected appeals came from Tehran prosecutor Abbas Jafari Dolatabadi, according to the Al Jazeera report. Dolatabadi had previously made headlines by vowing that the Islamic Republic would not “surrender to threats” posed by political detainees in Rajai Shahr Prison who have been on hunger strike for as much as three weeks over their forcible transfer to a ward with more repressive infrastructure including 24/7 video monitoring and obstructed ventilation.

The transfers and subsequent dismissive reaction to the hunger strikes appear to be aimed at silencing prisoners who seek to remain politically active or to call attention to the state of the Iranian prison system. The arrests of Americans and US-linked individuals have been variously cited as examples of a much broader crackdown on reformist and pro-democracy voices in the Islamic Republic. Although Rouhani promised a more open Iranian society, rates of arrest have reportedly increased, more than 3,000 people have been executed over the past four years, and the administration has given little to no pushback against hardline policies and initiatives.