Once they do? Stuxnet was what, 2010? And because of the coding error that caused it to spread outside the enrichment plant it was found out and only set them back something like 2 years.

From AP:

Iran, after the collapse of its 2015 nuclear deal with world powers, has pursued nuclear enrichment just below weapons-grade levels. Tehran has accumulated enough enriched uranium to build several weapons if it chooses. However, U.S. intelligence agencies and others assess that Iran has yet to begin a weapons program.

Iran is “presenting a face which is not entirely transparent when it comes to its nuclear activities. Of course this increases dangers,” Grossi said. “There’s loose talk about nuclear weapons more and more, including in Iran recently.

Since 2022, Iranian officials have spoken openly about something long denied by Tehran as it enriches uranium at its closest-ever levels to weapons-grade material: the Islamic Republic is ready to build an atomic weapon at will. That includes Kamal Kharrazi, an adviser to Iran’s Supreme Leader Ayatollah Ali Khamenei, who told Al Jazeera that Tehran has the ability to build nuclear weapons but does not intend to do so.