New York magazine has put it quite succinctly:

‘The simplistic, paranoid interpretation of what’s happening with Iran — wherein the U.S. is floating plans for an invasion and hyping intelligence of Iranian attacks — is that ultrahawkish aides are trying to manipulate their toddler president into war. Unfortunately, there is a lot of evidence suggesting this interpretation is correct.

The driving force is national security adviser John Bolton. During the Bush administration, Bolton sought without success to ramp up conflict with Iran. President Trump hired Bolton because he liked his tough-talking Fox News persona, but made him promise when he took the national security adviser job not to start any wars. Trump has repeatedly expressed his concern in private that Bolton is in fact trying to start wars, especially with Iran.’