Your ignorance is near complete.
Before 2018, ties between Iran and the West were beginning to thaw for real. I remember Iran even opening up to individual tourism. There was a nuclear deal in place supported by the entire international community (except the Netanyahoo regime). The situation had indeed begin to normalize.
Then came Trump, like the manipulated ignorant manchild that he is, and unilaterally and unnecessarily pulled the US out of the deal, at Netanyahoos behest. Destroying years and years of hard fought diplomacy in an instant. Annoying an entire world, including our allies, and unnecessarily antagonizing Iran. He then later, among other provocative actions, proceeded to move the US embassy from he capital Tel Aviv to Jerusalem. A completely unnecessary move, again antagonizing Iran and the entire Muslim world, and again at Netanyahoos behest.
All causing more unrest, division, anger and violence leading up to today's war.