I am one of the "older people" AGA but I don't feel that the US is neutralising a threat to the US. At nearly 87, maybe I am an earlier generation to the postwar "baby boom" and those younger even than that. They are who a lot of journalists consult when they want views of "older people" to quote. Perhaps if those generations were a little older still, with memories or family stories about why it is not wise to “just go along with Trump with little thought of why he is doing this.” they would answer differently.
Experts have said that Iran posed no threat to them, though I wouldn't rule out a grumbling resentment against the US. This war is not neutralising a threat, it is aimed at disabling a trading competitor so as to ensure the US dollar's position as chief currency for oil transactions. Trump is doubtless hoping also to enhance his own glory, and his bank account too by some means or other.
The biggest global threat I can see at the moment is that Trump's erratic pursuit of violence, and his threat of it as the way to answer all international questions, could draw more countries into taking up arms and using them to either resist him or support him. The sum of the financial support of all the non-US NATO countries is close to equalling that of the US (and they are all increasing their contributions, some able to do so faster than others)
NATO countries are aware that all need to stand firm together, ready for any moves by the likes of the bear against one or more of them, but in the engagement at the moment this is not one of those moves - unless it becomes so in response to the moves of a predatory bald eagle, or someone does something precipitate to make it so.
Within NATO, the US is one among 32, surely the other 31 could vote against any unwise decision made by one among them, whether a financial or a military one? In any case, once a military decision is made, each country decides for itself whether to join in, and how much in the way of men or equipment to commit. The US can do as much or as little as they want.