It’s been called President Obama’s signature foreign policy achievement -- so why does the Trump administration think it was the “worst deal ever” made?

On this season of Things That Go Boom, we’ll take a look at the Iran deal -- but this isn’t an Iran deal explainer. This is a story about how America stays out of a nuclear war. And the answer is messier than you might think. The government does not have it all figured out. Even good deals can be flawed. And swampy dynamics in Washington have the potential to send us all down a dangerous path fast.