US government rhetoric against Iran has lately hit levels not seen since the Bush administration, and a string of events over the last couple of weeks in and around Yemen appears to be the reason for it. US drone strikes and airstrikes against targets in Yemen took place before, during and after Trump's inauguration, but it was the US Special Forces (Navy Seals 6) raid in central Yemen on January 28th that got the US media's attention.
Two days after Trump's inauguration, US drones "killed five Al-Qaeda operatives" in central Yemen. This operation took place without Trump's knowledge (and thus without his approval) because his predecessor freed the Pentagon from executive oversight when it comes to drone warfare. The US war machine is, in a sense, sentient. It generally operates without any official leadership, decision-making or input from 'the civilian government'. The same goes for the multiple drone strikes conducted in 'ISIS-occupied' Syria and Iraq over the course of Trump's inauguration and first days in office.
So while most people might assume that all such operations would cease during the few days between the removal of the old administration and the institution of the new, yet that is not what happens, which is pretty clear evidence that US foreign policy operates independently of the White House.