This seems in-line with modern US military doctrine.

The US generally only wages wars of aggression against a nation as well-organized and well-armed as Iran when it can do them at arm's length with remote weapons and air superiority. Since the US has a volunteer army, actual risk to soldiers for something not perceived by the public as an existential threat jeopardizes future fighting efficacy.

The US public will tolerate missiles launched in its name; it is far less likely to tolerate video of entire Navy ships going down or sailors (not) coming home in body bags by the shipload for a cause that the administration didn't even try to sell them on as necessary.