I did a little research on the history of relations between Iran and the United States.
In World War II Iran was attacked by Russia and the UK. The us remained friendly with Iran.
In 1953, The CIA orchestrated a coup of Prime Minister Mossadeq. In 1957, the US helped Iran start it’s nuclear program.
In 1988, the US attacked Iran because of their secret development of nuclear weapons to help with their war against Iraq.
The 400 million dollar cash payment to Iran was to settle a claim by Iran to be paid for weapons they produced for the United States. The payment was frozen as a result of the sanctions imposed by the US and Europe. The reason for the payment in cash was because there really wasn’t any organized banking vehicle for Iran to accept the payment. Many would say that the cash payment was secretly made for the release of hostages which happened on the same day as the payment. It really doesn’t matter if Iran effected the motivation of the US to settle their dispute. At the end of the day, the claim was satisfied and the hostages were returned.
The Iran nuclear deal allowed the participating countries to continue to verify through inspectors that Iran was not developing uranium and other ingredients to make bombs. Many people don’t understand that Iran has been allowed to produce nuclear electrical power for their people.
Trump voted for an extension of the agreement in January 2018 then violated it in May 2018.
Rather than me try to recap the history between the US and Iran, I added a couple of links that provide more detail and timelines that I, could not accurately report.
One is a really good pdf put together by M.I.T. A second one is a pdf put together by Fortune, the third is a complete story of Iran by the Library of Congress.
Besides these reference links and in order to better familiarize myself on the topic, I researched articles and reports by Reuters, BBC, Wikipedia, MIT, Politico, the Library of Congress, the Aspen Institute, Brown University and 7 others.
M.I.T. PDF: http://web.mit.edu/mitir/2009/online/us-iran-2.pdf
Library of Congress: http://www.loc.gov/rr/frd/cs/pdf/CS_Iran.pdf
Fortune PDF: http://fortune.com/2016/08/05/money-america-iran/
I am sure our brilliant President doesn’t know the facts, so I might as well educate myself. You may find it interesting as well.