Why is the U.S. at war with Iran?

Regime change, nuclear weapons, terrorism …Why is the U.S. at war with Iran? In the days since the United States and Israel launched an attack on Iran, the Trump administration has given a wide range of reasons why the US is now at war. On Saturday, Trump seemed to indicate the U.S. and Israel were trying to clear the way for regime change. On Monday, Defense Secretary Pete Hegseth said the conflict in Iran was not about regime change. A couple of hours later in Trump's first public comments, not prerecorded on video, he listed four objectives. Regime change wasn't among them.