Earlier this spring, film director Asghar Farhadi wrote an emotional open letter on behalf of a woman who faced execution for fatally stabbing a man who had tried to rape her. Twenty-six-year-old Reyhaneh Jabbari has been behind bars for seven years after the man’s relatives demanded capital punishment under ghesas, a Sharia-based legal code based on reciprocal justice. Jabari’s case has stirred controversy at home and abroad, and has been the subject of a passionate debate in private discussions and the Persian-language blogosphere. Still, Farhadi had to craft his sentences carefully when addressing the issue in Iran’s public sphere, where an entirely different set of rules apply.

While Iran’s clerical establishment has been known to show a surprising level of leniency on a host of sensitive sociocultural topics, cornerstone Islamic legal principles such as ghesas present an immovable red line. One recent illustration is the March closing of the newspaper Aseman, which lost its publishing license after its editors made a passing reference to a critical discussion about ghesas in a bank-page article. Two days earlier, the same newspaper had, without ramification, printed a front-page feature about the first domestic publication of The Colonel, a politically charged novel that criticizes the1979 revolution and had been banned in Iran for decades.

To avoid prodding the system in one of its most sensitive spots, Iranian intellectuals and human rights activists have only one tool at their disposal. Since they cannot criticize the practice of ghesas and capital punishment itself, they emphasize the option of mercy, or rahmat, which allows victims to forgive the perpetrator up to seconds before the scheduled execution. While the ultimate choice between punishment and forgiveness rest with the victim or the victim’s relatives, a combination of social pressures and the system’s own preference to relegate ghesas to remedial punishments, such as fines or imprisonment, are highly influential. This results in periodic phenomena like the case of Balal, a young man whose 16 April execution was halted after the mother of the man Balal was convicted of killing relinquished her right to ghesas as Balal stood on the scaffold.

Unlike other categories of crimes in the Iranian penal code, which leave the administration of punishment in the hands of the Islamic jurisprudent, ghesas are crimes that involve murder and bodily injury, and thus emphasize the rights of the victim. In traditional Islamic societies, the families of a murder victim had the right to eye-for-an-eye retaliation that remains codified in the modern Iranian legal system. The difference is that the state - not the victims - are responsible for carrying out the actual punishment.

Reyhaneh Jabbari defends herself during the first hearing of her trial in 2008. Photograph: Golara Sajadian/AFP Photograph: Golara Sajadian/AFP

Under Iranian law, everything from sodomy to blasphemy against the Prophet Mohammad is subject to capital punishment, but only in the case of ghesas does the weight of the decision lie outside the realm of the state. Watchdog groups have warned of a general surge in the number of executions since the start of Hassan Rouhani’s presidency. However, Iranian legal scholars have also noted that on the whole, judges prefer to relegate a majority of capital and corporal punishments to monetary penalties, or deyet. But since the judiciary cannot directly influence the punishment for a ghesas case, the option of mercy and forgiveness, enshrined as it is in Sharia law, presents a unique opportunity for all groups striving to reform the system from within.

On one hand, mercy represents a lone bridge between rights advocates and Iran’s conservative ruling class, which has on multiple occasions demonstrated a willingness to reform human rights laws in the country if they are based on homegrown Islamic principles. International criticism of Iran’s human rights standards, such as the European parliament’s recent resolution, is generally poorly received by conservative political groups inside the country, who associate the outside pressure with colonialism and ulterior foreign policy motives. Still, the human rights topic presents an issue of legitimacy for the clerical ruling class, whose members struggle to reconcile the traditional reading of Sharia with modern legal norms emphasizing reconciliation over retribution.

“In the context of complex political wrangling within Iran’s multifaceted state, hard-line state agents move toward universal human rights by actually reclaiming an enlightened heritage and nativizing human rights as the measure of Islam’s capacity for mercy,” writes University of Washington scholar Arzoo Oshanloo.

On the other hand, mercy and “the spectacle of the scaffold” provide the system with a dangerous tool that demonstrates authoritarian power to domestic audiences while projecting a more humanitarian image of the country to international critics. “The Islamic Republic of Iran simultaneously mobilizes multiple modes of power in an effort to show how it is authentic and global, modern and Islamic, and perhaps most important, merciful and just,” Osanloo writes. “The spectacular performance of Islamic penal justice is an exertion of state power that lends greater credence to the authority of a modern state.”

The authoritarian nature of the state makes Brown University’s Mehrangiz Kar, a prominent human rights lawyer, skeptical about Iran’s ability to reform capital punishment laws according to its own rules. She points to the absence of an independent judiciary, as well as a highly politicized system in which judges and lawmakers are more concerned with preserving their own interests than reforming outdated laws and administering fair rulings. In addition, the Iranian legal system allows gender and creed-based discrimination, which is in direct contrast to basic human rights principles, Kar said. “One cannot be too hopeful about the reform of laws based on religious beliefs that assigns differential values to human life,” she told Tehran Bureau.

However, Kar notes that even Iran does not exist in a bubble. Since the strict interpretations of Shari’a were only imposed in recent decades, capital punishment is more controversial in Iran than elsewhere in the Middle East, as Iranian society “had no memory of these kinds of harsh punishments until the Islamic Revolution,” she said. This lack of experience means more social discussion and changing beliefs affected by international norms. However, impact on the system itself is low due to the dearth of spaces for free public discussion. “If we had freedom of speech, there might be hope of ghesas reform,” Kar said. “For now, all we have as an outlet is cyberspace, as anyone who criticizes the system from the outside gets accused of supporting Western imperialism.”

Still, the mercy concept allows a small handful of prominent figures to address public sentiments without falling outside the framework of regime-approved discourse. These include Adel Ferdosipour, the outspoken sports commentator whose pleas for forgiveness proved influential in Balal’s case, as well as director Farhadi, who supported Jabbari with a broad appeal for tolerance and solidarity.

“In our society, forgiving even in small doses has been forgotten,” he wrote, addressing the family of Jabbari’s alleged assailant on the front pages of the reformist daily Shargh. “Perhaps it is more meaningful for your loss to forgive [Jabbari] for the sake of humanity.”

The Tehran Bureau is an independent media organisation, hosted by the Guardian. Contact us @tehranbureau. This article was originally published without a byline