In 2003 the Supreme Leader of Iran, Ayatollah Ali Khamenei, along with other clerics, issued a public and categorical religious decree (fatwa) against the development, production, stockpiling and use of nuclear weapons, though it is approved by some relatively minor clerics.

Iran does not yet have a nuclear weapon, but it has a long history of engaging in secret nuclear weapons research in violation of its international commitments. Western analysts say the country has the knowledge and infrastructure to produce a nuclear weapon in fairly short order should its leaders decide to do so.