Like the other guy said, that was not a war. The casualties were minimal, and Iran is still where it used to be. That was a scary moment indeed, but luckily nothing serious came out of it.
Also, I'm quite surprised that someone else is still reading this conversation. Wow.
But, sure, if we arbitrarily exclude some international armed conflicts between military forces of one country and those of another from “war”, then, ok, you can rescue the claim that Trump hasn't started any “wars”, but at the cost of weakening the case for excluding other Presidents from that same description.
* Obama: Libya (in ruins), Syria (in ruins)
* Bush: Iraq (conquered, then partially reconquered back by ISIS), Afghanistan (yet another never-ending Afghan war)
* Clinton: Serbia (ended up relatively OK, had to elect a new president, give away the old one, and also a part of the country declared independence), and I think there were more? I was a kid back then, don't remember it well, need to wiki up.
* Old People's Bush: Gulf War, and I guess wiki would tell more stories.
These all are large conflicts with non-trivial outcomes. Lots of troops involved, lots of casualties caused, serious consequences for the countries attacked. Now, what are the casualties for that T's conflict with Iran? What are the consequences for Iran?
Checked wiki [1]: 7 combatants dead on the U.S. side, 22 on the Iran side (of which 19 is friendly fire), in the grand scheme of things - no consequences so far.
Also, if we need a relatively neutral third party, then English Wikipedia calls these events not "war" but "crisis" [1] and does not list it in their list of U.S. wars [2]. Feel free to try to add it to that list and prove your point to fellow wikipedians, I'd watch how it would go.
Also, I'm quite surprised that someone else is still reading this conversation. Wow.