Bombing this sites is in line with US policy that Iran can not be allowed to have a nuclear weapon. He gave Iran the chance to negotiate and they dragged the talks until things eslxates with Israel. Even after the attacks started he still left the door open for talks which the UK and EU leaders tried to meditate over the past few days which didn't go anywhere so the decision was take advantage of the current situation where the Iranian regime is on the back foot and weak and strike a decisive blow to their nuclear ambitions once and for all or stay out and we deals with this in another year or two.
Israel has show it can defeat Iran with all their bluster but only the US has the capability to destroy the nuclear sites which are built deep underground with the use of the buster bomb, and only the US has a plane which can deliver the bomb, the B2 bomber.
So yes you can argue that seriously damaging Iran's nuclear ambition is actually America first. He made it very clear when he opened the doors to negotiate with Iran that they will NOT be allowed to have a nuclear weapon. Who knows maybe the bloody regime will fall and Iranians can rebuild their country.
Iran's allies the terrorists groups that they sponsor are all weakend, Hezbollah, Hamas and Houthis so they are very weak right now, they will bluster and shout and maybe attack a US base in Iraq or something just to save face then stfu.