After intense negotiations, Nazanin Zaghari-Ratcliffe has finally been freed from captivity in Iran where she has been since 2016.
British-Iranian citizen Nazanin was detained on suspicion of plotting to overthrow the Iranian government while she was taking her one-year-old daughter to visit family.
Her passport was returned to her earlier this week, and she is flying home to the UK on a government-chartered flight.
News of her release comes as welcome relief to Brits - none more so than Nazanin’s husband, Richard Ratcliffe, who spent three weeks on hunger strike in autumn 2021 as he petitioned the UK government to do more for her release.
But behind Nazanin’s imprisonment was the small matter of a £400 million debt that the Iranian government claims to be owed by the UK.
Why does the UK owe Iran £400 million?
The UK owes the money to Iran because it failed to deliver an order of tanks to Iran in the 1970s.
On Sunday March 13 2022, Iranian state media said the debt had been paid - a claim that hasn't yet been verified by the UK.
The tanks themselves were promised to the Iranian Shah in 1979, who was then dramatically ousted by a new Islamic republic. Britain delivered just 185 of the 1,500 tanks promised by the time the old government fell to the revolutionaries.
When the new government insisted the UK needed to repay the money for the undelivered tanks, the UK said it owed the old government, not the new one.
In 2009, the international arbitration court ruled that the UK did in fact owe the money to the new government as a ‘successor state’.
However, international sanctions placed on Iran meant the debt could not be repaid without breaking the law - leading to a diplomatic spat now in front of us today, which may well have left Nazanin and her family as the ultimate victims.
On Monday, foreign minister James Cleverly told BBC Radio 4’s Today Programme: "The situation with regards to the... military contract from the 1970s which has dragged on for decades, those negotiations are ongoing. They have been for a long while, sadly, but they are ongoing.
"There's a legal process tied up with this as well. Iran most recently stepped away from that legal process, which has of course delayed things.
"We are looking at ways of resolving what has been a multi-decade long problem."
How are Nazanin and the £400 million linked?
Mrs Zaghari-Ratcliffe believes her imprisonment was leverage in Iran’s quest to recover the cash, something the British government resolutely denies.
“There are two entirely separate issues," said PM Boris Johnson, a sentiment echoed by Cleverly in his interview.
"The reports that we had over the weekend linking that work with the incarceration and the arbitrary detention of British dual nationals I think was completely inappropriate - they are separate issues, one massively predates the other."
He added the imprisonment "should be unlinked to the multi-decade-long dispute with regard to the tanks".
