The money was sent on an unmarked charter plane via Switzerland. It was then converted into other currencies including euros and Swiss francs, and then Iranian aircraft took the cash in three goes. The first lot of cash, around $400 million, was stacked on wooden pallets.

Sources say that Iran has used a large portion of it to fund its proxy groups, in particular the notorious Lebanese Hezbollah. A large part of the funds has also gone to various elements of Iran’s Islamic Revolutionary Guard Corps (IRGC), to its Quds Force and to foreign intelligence groups.

Some of the American money was spent on the Houthi rebels in Yemen. Iran has been involved in the conflict in Yemen where it supports the Houthis that are trying to control of the country.

It is expected that this intelligence will have a huge bearing on future actions taken by President Trump. Trump has already voiced his criticism of his predecessor, slamming him for giving Iran so many concessions and for negotiating a really weak deal. He also criticised Obama for his inaction with regards to Iran’s belligerence.

Last month he criticised the transfer of American money to Tehran: “The enormous financial windfall Iran received because of the deal — access to more than $100 billion, including $1.8 billion in cash — has not been used to better the lives of the Iranian people. Instead, it has served as a slush fund for weapons, terror, and oppression, and to further line the pockets of corrupt regime leaders.”

Trump explained that he is working to cut the flow of money to Iran so that it cannot financially support proxies and militias in the region. So far, almost a hundred entities and individuals that have supported the Iranian ballistic missile program and other illicit activities have been sanctioned.

The first payment of $400 million created controversy because it coincided with four American hostages being released by Iran. There were inevitable claims that Obama is paying a ransom for their release. Obama tried to justify the cash movement by saying that the US would lose a court case regarding arms purchases made by the US if it did not hand over the cash.

Obama’s administration tried to appease Iran with the cash, but the Trump administration is taking a new route to curbing Iran’s threat by taking a harsher course of action.

James N. Mattis, the US Defence Secretary has said that the Trump administration is taking a hard stance on Iran and that the Iranian regime, despite the nuclear deal and despite the recent popular uprising, is still continuing to “sow violence and remains the most significant challenge to Middle East stability.”