Iran has several research sites, uranium mines, a research reactor and several uranium enrichment facilities. Its programme began in the 1950s with support from the U.S under the “Atoms for Peace” program. Iran has been a party to the Nuclear Non-Proliferation Treaty (NPT) since 1970 and so it is legally bound not to develop or acquire nuclear weapons.

In 2002, Iran was accused of secretly working on the development of nuclear weapons which led to an investigation by the IAEA and a resolution in the United Nations General Assembly calling on Iran to suspend its programme. The IAEA concluded there was evidence Iran had worked on a plan for a nuclear weapon, but there was no evidence this was continuing, and U.S. intelligence has concluded that Iran abandoned plans to develop nuclear weapons in 2003.

In 2015, following talks with the five original nuclear-armed states, China, France, Russia, the UK and the US, plus Germany, Iran agreed to limitations on its nuclear programme, including the enrichment of uranium and reduce the size of its stockpile of enriched uranium, in return for the lifting of sanctions.

In 2018, then President Trump took the US out of the JCPOA deal and reimposed sanctions. In response, Iran has incrementally violated provisions of the deal in an apparent effort to put pressure on the other parties to the deal to bring the US back into compliance. Under President Biden, efforts to agree to a US return to the deal and an Iranian return to complete compliance have so far been unsuccessful.