Reza Ramezannejad, an energy company executive who is active on Iran social media, pinned a photo of a nuclear site to his profile page in January and wrote, “God willing, soon there will front-page news that Iran tested nuclear warheads on domestic missiles.”
In Israel, which considers Iran its most potent foe, many Israeli leaders, particularly Mr. Netanyahu, had welcomed Mr. Trump’s repudiation of the nuclear deal. They have also expressed alarm that Mr. Biden appears ready to re-enter the accord, arguing that it is too weak.
Mr. Biden and his subordinates have argued that Mr. Trump’s strategy was counterproductive because Iran is no longer complying with the deal’s restrictions, effectively shortening the timeline Iran needs to build a nuclear weapon.
The assessment released Tuesday by the intelligence division of the Israeli Defense Forces, along with an earlier assessment by the Mossad, Israel’s intelligence agency, suggests that Iran remains at least two years away from such capability.
Israeli intelligence officials, who spoke on condition of anonymity when discussing Iran’s nuclear activities, said they believed that Iran had amassed uranium sufficient to build almost three nuclear bombs — if the uranium were enriched to weapons-grade level. The officials said such enrichment was theoretically attainable in about five months.
But the Israeli intelligence assessments said Iran still lacked the scientific and technical wherewithal to make a weapon. One senior Israeli commander, briefing journalists in Israel, said the assassination in November of Iran’s top nuclear scientist, Mohsen Fakhrizadeh, had delivered a severe blow.
Iran has blamed Israel, abetted by the United States, for the killing of Mr. Fakhizadeh, long identified by American and Israeli intelligence services as the guiding figure behind what they have called “the Weapon Group,” a covert effort to design an atomic warhead. Iran has said Mr. Fakhrizadeh devoted himself to peaceful applications of nuclear science.
Reporting was contributed by Pranshu Verma, Michael Crowley and Isabel Kershner.