This is not a question of "if" or even a question of "when" because the US has been an active belligerent from day 1.
>green light the attack on Iran
>take a very active part in shooting down Iranian missiles and drones they send in retaliation

It's been happening since the very beginning. The US lets Israel do the attacking so Trump can appear reluctant, but they defend Israel against retaliation. And if the kikes can't win on their own, the US will 100% go on the offense. The Nimitz and co are already on their way. Trump and the entire political elite in the US is Israel's loyal dog, the beef between Trump and Bibi is 100% fake, and let me fuckign say this to you again
>the US has been heavily involved in the fighting since day 1
Which also means:
>Their military assets are legitimate targets
>and the same goes for any NATO vessels, air squadrons, or Gulf State assets that took part in defending Israel from Iran's retaliation.
But despite this, should Iran rightfully yet foolishly take a shot at American assets, the entire globohomo media will cry unprovoked aggression, since the fact that the US is actively defending Israel from Iran's retaliation was not widely reported, and many people don't know of it.

Also, the entire EU is in Israel's pocket as well. Even if there are a couple dissenters, usually leftistss (how how the turntables), UvDL and the EU commission and most mainstream parties in the EU are 1000% Kosher and will back Israel. This means, that besides the US, the entirety of NATO can also be expected to get involved even heavier than they are right now, should the need arise.

To conclude, TL;DR
>Either Israel achieves its offensive objectives while it's already being defended by the US and its puppets, so Trump and his cronies can remain in the role of "reluctant peace lovers"
>or The US and its puppets get more heavily involved, after a very intense media smear campaign against iran and possible false flags

No other option.