> Iran has long said they're not working on nuclear weapons. However, they have built a large stockpile of particles of rich uranium, which is something completely useless to have unless you're planning on building nuclear weapons.

After the JCPOA the stockpile went to zero (esp. >5% enrichment):

* https://www.statista.com/chart/23528/irans-stockpile-of--low...

* https://www.armscontrol.org/factsheets/status-irans-nuclear-...

* https://www.forbes.com/sites/niallmccarthy/2020/11/18/the-de...

One year after the US left JCPOA (during Trump 1.0) the stockpile started going up again.