A brief look at how Iran's 'hostage diplomacy' evolved since 1979

On 4 November 1979, more than four decades ago, Islamist Iranian students stormed the US embassy in Tehran and took 62 American staff hostage. That crisis lasted 444 days—a moment few imagined would help define Iran's foreign policy for decades.

The recent conditional release of a French couple, as a British couple remains imprisoned, has once again brought the issue into the spotlight. 

Today, arrests on vague national-security charges and prisoner-swap negotiations have arguably become one of the main pillars of Iran's diplomacy. 

Who's targeted? 

After the US embassy crisis, theocratic rulers of Iran did not repeat the drama of mass hostage-taking. Rather, they shifted toward targeted arrests of foreign individuals, including tourists, dual nationals, academics, and foreign journalists, often under the accusation of espionage or "acting against national security."

During the Lebanese civil war of the 1980s, Iran's influence over armed groups helped shape the fate of several US hostages kidnapped in Beirut. These abductions later became part of clandestine weapons negotiations, infamously known as the Iran-Contra affair.

In 2016, as implementation of the ill-fated nuclear deal began, Iranian-American journalist Jason Rezaian and four other US citizens were released in a bargain that included the settlement of a decades-old financial dispute between Washington and Tehran.

A similar dynamic shaped the case of British-Iranian citizen Nazanin Zaghari-Ratcliffe, who was held from 2016 until 2022, when the UK finally paid a £400 million debt to Iran dating back to the Shah's era.

Zaghari-Ratcliffe's detention prompted repeated accusations that Iran was using her as leverage. For its part, Amnesty International stated that Iran's treatment of Zaghari-Ratcliffe "amounted to the crime of hostage-taking" and relied on "spurious national-security charges" to pressure the UK government.

At her first press conference after returning to London, Zaghari-Ratcliffe herself said, "The meaning of freedom is never going to be complete until all who were detained in Iran are reunited with their families."

Tehran has increasingly sought the return of intelligence operatives or individuals arrested abroad for terrorism or sanctions-busting by detaining Western citizens inside Iran. This notably included the swaps of Iranian diplomat Asadollah Asadi, convicted in Belgium for plotting attacks in Europe, and Hamid Nouri, tried in Sweden for his role in the 1988 prison massacres.

At the same time, Iran's targeting of dual nationals allows the state to negotiate quietly, with minimal public scrutiny.

Over the years, this has given the Foreign Ministry a central role in managing detainee cases, specifically when arrests originate with intelligence agencies or the Revolutionary Guards.

'Hostage diplomacy'

Iran's use of foreign detainees as bargaining chips reshaped much of its diplomatic relationships, with a strategy of creating cycles of crisis, negotiation and partial resolution.

Various human-rights groups warn that, because these detentions often go unchallenged as state hostage-taking, Iran has grown more confident in using them. 

The recent release of Cécile Kohler and Jacques Paris, two French citizens detained in Iran since 2022, highlights how hostage diplomacy functions in Tehran's foreign policy. Their release appears closely linked to the fate of Mahdieh Esfandiari, the Iranian held in France.

Former detainee Xiyue Wang, a US citizen imprisoned in Iran from 2016 to 2019, explained this strategy when he recalled that, during his imprisonment, the interrogators told him that they needed a deal with the US.

"They said, 'We want our money back from the United States. We want our detainees back, and you have to be a spy for that to happen'," Wang noted.

The June 2024 prisoner swap involving Hamid Nouri, convicted in Sweden for crimes against humanity, and two Swedish citizens held in Iran, was another example, showing that hostage diplomacy remains a core part of Tehran's foreign policy.

Critics called the deal "a grotesque miscarriage of justice," arguing it rewards arbitrary detention and undermines accountability for human-rights abuses. What made that swap symbolic was not the release of detained Western citizens, but that Iran secured the return of a man convicted of involvement in the mass execution of leftist prisoners.

The exact number of foreign nationals and dual citizens held in Iran currently remains unclear, with estimates ranging from 20 to 40 individuals. 

Ultimately, Iranian authorities have shown that they do not hesitate to target individuals when they need leverage for a prisoner swap. The Nouri exchange underscored that in each release, Iran's tactic of "hostage diplomacy" has only deepened.