It doesn't make the US look weak or powerless, I see it more as the US tried to negotiate to avoid Israel attacking, but Iran being the hot heads they are dragged the talks until Israel attacked.
If the US went down the military route first we would be calling Trump a warmonger who wants to start WWIII, yet he tried negotiating whilst also making it clear that Iran will NOT be allowed to build nuclear weapons and we also claim he is weak and powerless. He made it very clear to Iran that he is willing to work with them so they either go down the path of negotiations or the path of destruction and I guess they choose destruction.
I am actually happy that the US is not involved in the strikes yet they benefit indirectly from a weakened Iran. Let's see how things go with Iran's response and if this will escalate into a full war or not.
I think not because Iran was already in a weakened state before this attack and the attack caused a lot of damage so they may just retaliate with drone and missile strikes to save face many of which will be stopped by the iron dome rather than launch a full war on Israel.