In the cases you mention it is not proven that Iran was the actor.
What you call terrorism is the same as the US presence there- influence. In fact Soleimani forces were important for halting IS in Iraq.
The drone was downed because it was in Iran's territory, so they had a right to do that.
Iran was so wise not to kill Americans in the revenge attack after Soleimani's killing, to avoid a war. Unlike Trumps behaviour that almost started one.
The US is the aggressor - That started with blowing up the Iran-deal and the imposing of very strict economic sanctions.
Since then US provocative military action have tried to trigger a reaction from Iran to find an excuse for further military interventions...
Before all that Iran was going the right way, its nuclear program was controlled and there was room for the moderate political forces in the country. Those voices have now been silenced.
Your first line pretty much tells me everything about what you think.
Fact is Iran for months now has been provoking the west, not just the USA, including the attack on the embassy. Trump, and the rest of the west, did nothing until Iran killed an American. Iran is the agressor; we were just re-establishing deterrents.
Answer me this, if, as you put it, "The US is the aggressor," with much of Europe supporting the Iran deal, then why did Iran attack Europe bound oil tankers? You would think that if Europe was on Iran's side, Iran would want to appease the Europeans as much as possible and not attack oil shipments bound for Europe. But this is not what happened, exactly why?