In this case it's especially depressing that the war's rationale exists only because Trump wanted to tank the deal made by Obama. Which was not a perfect deal but better than the status quo back then, and much better than any likely outcome of this war.
Politics will exist for as long as there are people.
Any country not able to or interested in waging occasional war will be destroyed by countries that can and do.
Simple as that.
But please I'm interested in hearing any utopia arguments that claim we can/should deprecate war. And remember - you have to convince your country along with every other country.
You could at least say something like "we have to bomb the people so they can be free" or "don't you know the Iranians were seconds away from nuking new York, because they have no regard for their own survival".
We should "deprecate" offensive wars of choice based on lies because the opportunity cost is enormous (what could we have bought with the 200+ billion they're already looking to spend here?).
Every time we do this we create more terrorists (see the blowback incidents weve already had from this war), which results in more egregious government overreach on the domestic population (see patriot act and the experience of commercial flight in today's world).
And those are just some of the basic reasons. I don't have time to write them all.