The phrase "warmonger" doesn't specify anything about the nature of the war, or the reason it was started. It's a very simpleminded "war=bad". If that's how we will be judged, fine.
As soon as you use the phrase "unprovoked" then you start getting into messy details. Are we so sure that the war in Ukraine was not provoked by NATO expansion? Are we so sure that the war in Iran was not provoked by Iran's actions against Israel or against its own people?
The ideologue doesn't like details. They prefer to see the world in black and white.
warmonger - noun: one who urges or attempts to stir up war
And to preempt the inevitable "the dictionary isn't always how people use it" response, this is in fact how everyone uses the word.
So yes, it's very much tied to the nature of the war and the reason it was started. Attacking Iran for no particular reason is warmongering. Defending Ukraine from invasion is not.
"Unprovoked" can be difficult but I don't think it actually is here. Yes, you can list reasons. But even if you believe the wars' proponents, the justification isn't there. It's like if I tap someone on the nose and they blow my head off. Was there some provocation? Technically, yes. Does the killing count as "provoked"? Not really. That word carries an implication of sufficient, justified provocation, not just "something happened."
Did NATO expansion provoke the invasion of Ukraine? Maybe. Is that sufficient to say the invasion was "provoked"? No, not even close. Similar for the justifications given for Iraq and Iran.