Commenting on Prime Minister Boris Johnson's phone call with President Hassan Rouhani, demanding the return of of Nazanin Zaghari-Ratcliffe and other British-Iranian Nationals, Dr Anicée Van Engeland, Associate Professor of International Security & Law at Cranfield University, said: “There are two games of chess occurring and Nazanin Zaghari-Ratcliffe is caught up in both. One is the historic debt that the UK has to Iran and the other is in relation to Iranian nationals imprisoned in the West.

“While both nations have denied publicly that her case is linked to the debt, the UK’s decision to acknowledge it points to this being the reality of the situation. Until the issue of Western debt to Iran is resolved, cases like Nazanin Zaghari-Ratcliffe’s and other dual-national citizens will continue to be caught up in this geopolitical issue. Iran is also conscious of a number of what it considers ‘political prisoners’ held in the West.

“This case is, yet again, another example of how the Iranian authorities use domestic law to maintain their political legitimacy. Iranian national security laws were changed in 2012, and yet again in 2018, so that the authorities could specifically crackdown on the crimes that Nazanin Zaghari-Ratcliffe has been charged with. Most dual-nationality citizens, particularly journalists and academics, have been arrested, prosecuted and convicted under these measures.     

“In the West, terms like ‘hostages’ are used to describe dual-nationality citizens currently imprisoned. However, it is important to understand the way these cases are interpreted in Iran, because the Iranian authorities are much more concerned about the views of the Iranian public than they are of Western Governments. By creating a legal basis for prosecuting these cases, the Iranian authorities are able to shield themselves from Iranian public opinion under the legitimacy of upholding the law.

“Ultimately, cases like Nazanin Zaghari-Ratcliffe’s and that of other dual-nationals imprisoned in Iran will continue until the geopolitical issues of debt and Iranian nationals held in the West are in part resolved.”

Dr Van Engeland is a leading expert on Iran and has previously given evidence in front of the Foreign Affairs Select Committee inquiry into the UKs relationship with Iran.