If it were that straightforward, right now the US would (A) have a consistent set of demands/goals that include shipping security and (B) a large international coalition of support.
Neither are true.
P.S.: Plus, of course, the whole problem where "protecting global sea lanes" typically requires a different approach than "start a war by assassinating the leadership you were negotiating with."
US messaging has been all over the place, but stop funding proxies has been one of the more consistent parts.
To be clear, im not saying protecting shipping is the primary reason for this war. I'm just saying if that is what you think usa should be doing, then this war makes sense.
As far as b) there are a lot of factors. Its not like freedom of navigation is the top concern of every country in the world.
JD vance whined that we shouldn't protect middle east shipping lanes because he believes it helps Europe more than the US.