The US is going to leave the Iran deal by choice of US president Trump.
The US will pull out of the treaty made by Trump's predecessor Obama. Today at 8 May 2018 Trump made the decision to not re-certify the Iran deal.
Future predictions over what could happen are not clear. Iran could reboot its nuclaer program and start and arm's race in the gulf.
Benjamin Netanyahu, Prime minister of Israel, is also against the treaty because he states that Iran is still working on their nuclear program.
Trump called the deal "The worst deal ever"