There is still lots of evidence that Iran started enriching uranium towards weapons grade over the past decade. https://www.bbc.com/news/world-middle-east-64810145 Largely a legacy of Trump's sanctions failing to get a nuclear deal the first term and back firing. You'd have to be naive to think they don't want a bomb in the first place before that though.

Saddam played the same game where they pretended they just wanted nuclear for energy, even though they were a petrol state... which is why in 1981 Iran helped bomb Iraq's reactors (where Iran teamed up with Israel to do so) https://en.wikipedia.org/wiki/Operation_Opera

If Iran didn't believe Iraq's peaceful nuclear intentions, I'm not sure why anyone would believe Iran then buying tons of uranium from Russia was any different. Not to mention building underground lairs to enrich it while also building ICBMs.