US and Israeli strikes on Iranian nuclear facilities have likely degraded Iran's ability to develop a nuclear arsenal. US and Israeli strikes damaged or destroyed the Fuel Plate Fabrication Plant (FPFP) and Uranium Metal Conversion Plant at the Esfahan Nuclear Technology Center (ENTC), both of which are used in the final steps of building a nuclear weapon.[1] These facilities could have supported metallization, which is the process of converting uranium hexafluoride into dense metal for an explosive core.[2] A nuclear analyst at a Washington, D.C.–based think tank reported on July 2 that US and Israeli strikes on Iran's uranium metal conversion facilities at the ENTC did not significantly delay Iran's nuclear timeline.[3] The analyst stated that Iran could still produce enough uranium metal for a nuclear weapon (25 kilograms) in “weeks, perhaps even days” without these facilities.[4] The analyst assessed that Iran likely already knows how to produce uranium metal, citing an International Atomic Energy Agency (IAEA) report that stated that Iran produced over 100 kilograms of uranium metal from green salt at a laboratory in Tehran between 1995 and 2002.[5] CTP-ISW previously assessed that, if Iran were to pursue a nuclear weapons program, it would likely pursue a nuclear arsenal rather than a single nuclear weapon. A nuclear arsenal would require more than 25 kilograms of uranium metal and significant amounts of highly enriched uranium. The Institute for Science and International Security previously assessed that US and Israeli airstrikes on Iran's main enrichment facilities, Fordow and Natanz, “effectively destroyed” Iran's enrichment program and that it will take a “long time” for Iran to restore its enrichment capabilities to pre-strike levels.[6] Large enrichment facilities like Fordow and Natanz would likely be necessary for Iran to develop nuclear weapons at scale.
Iran would also need to miniaturize a nuclear warhead to mount it on a ballistic missile. Iran could attempt to build a simple gun-type nuclear bomb, which is similar to the one the United States dropped on Hiroshima. A gun-type nuclear bomb needs 25 kilograms of 90 percent enriched uranium. The New York Times reported in February 2025 that a secret Iranian team may have been working on a faster way to build this type of bomb.[7] US officials said that the design would not fit on a missile and would be less reliable than a modern warhead. Iran would have to use an aircraft or another crude delivery method with this type of nuclear weapon Iran would also need the facilities and expertise to build even a simple gun-type bomb. Israeli killings of Iranian nuclear scientists and US-Israeli strikes on Iranian nuclear facilities likely degraded that capability.[8] A US weapons expert noted that US and Israeli strikes have “significantly” increased the time required for Iran to “build even a non-missile deliverable weapon,” such as a gun-type nuclear bomb.[9]
Israel is reportedly drafting a mechanism to prevent Iran from being able to rebuild its nuclear program following the conclusion of the Israel–Iran War, according to Israeli media.[17] The mechanism is reportedly similar to the US-approved Israeli mechanism for monitoring the ceasefire in Lebanon that allows Israel to conduct preemptive operations against Hezbollah if Hezbollah violates the November 2024 Israel-Hezbollah ceasefire agreement.[18] Israeli Defense Minister Israel Katz previously stated that Israel would pursue a “policy of enforcement” to prevent Iran from rebuilding its nuclear capabilities, air defenses, and missile production.[19] Israeli Prime Minister Benjamin Netanyahu will reportedly discuss the draft mechanism with US President Donald Trump next week.[20] Israeli media added that Israel is conducting “under-the-radar” talks with Russia regarding Iran and Syria, but did not specify what Israel has discussed with Russia.[21]
Israel destroyed a large number of Iranian ballistic missile sites during the Israel–Iran War. see text
https://www.understandingwar.org/backgrounder/iran-update-july-3-2025