Iran expanded the ambit of the West Asian conflict and launched an unsuccessful twin missile attack on Diego Garcia, the joint US-UK military base some 3,800 km away in the Indian Ocean, even as the UN nuclear watchdog confirmed that key Iranian nuclear facility at Natanz was targeted in a fresh strike on Saturday. Iran also claimed to have hit an Israeli F-16 fighter jet.The Diego Garcia attack showed Tehran’s hidden ability that it had missiles that could travel almost 4,000 km, a possibility flagged in January by ‘Iran Watch’, a think-tank operated by US-based Wisconsin Project on Nuclear Arms Control.One missile reportedly failed in flight while the other was intercepted by a US warship mid-flight. The Diego Garcia base is on a small, remote atoll but is strategically located and capable of accommodating long-range bombers. It has been used as a launchpad for operations in West Asia for years.Iran launching a 4,000-km-range missile has propelled it into a select league of nations, including the US, India, China, Russia, UK, France and North Korea. Tehran had earlier declared a missile range limit of 2,000 km.Western analysts pointed out that Iran probably used Khorramshahr-IV to attack Diego Garcia. ‘Iran Watch’ had, in its January assessment, said the missile was “likely deployed”, and that it “could almost certainly reach longer ranges (greater than the declared 2,000 km) if equipped with a lighter warhead”.For a missile to travel 4,000 km, it takes a parabolic arc, exiting the inner atmospheric core of the earth and then re-entering to hit the target. A missile of 3,000-km-plus range is classified as intermediate range ballistic missile (IRBM).Since the 1980s, Iran has set up its missile project and slowly improved the manoeuvrability of its re-entry vehicles and warheads. The country has an active missile research and development programme based at Shahid Hemmat Missile Industries Complex in Tehran.The US Congress in June last year made an assessment ‘Iran’s Ballistic Missile Programs’, which said, “Iran continues to bolster the lethality and precision of its domestically produced missile and has the largest stockpiles of these systems in the region.” The US National Air and Space Intelligence Center catalogues at least 14 Iranian ballistic missile variants.The US Institute of Peace has expressed concern about the potential dual purpose of Iran’s space launch vehicle programme, noting that it could be used to develop ballistic missiles.On the technology front, Iran has probably been inspired by the North Korean systems. The Khorramshahr appears to be based on North Korea’s Hwasong-10 IRBM, which is referred to as ‘Musudan’ by the US intelligence. Its range is estimated to be between 2,500 and 4,000 km, which exceeds the 2,000-km range limit claimed by Iran for Khorramshahr.Meanwhile, UN nuclear watchdog International Atomic Energy Agency (IAEA) has confirmed that Iran’s key nuclear facility at Natanz was targeted in a fresh attack on Saturday, even as it reported no increase in off-site radiation levels.In a brief statement on X, the IAEA said it had been informed by Iran that the Natanz enrichment site had been hit, and that it was closely assessing the situation.IAEA Director General Rafael Grossi reiterated an urgent call for military restraint, warning that continued strikes on nuclear facilities could trigger a dangerous radiological incident.The development comes amid intensifying military activity involving Iran and Israel, with nuclear infrastructure increasingly emerging as a potential flashpoint in the widening conflict.Preliminary reports indicate that while the site was struck, no radioactive leakage was detected outside the facility, suggesting that any potential impact remained contained for now. However, experts cautioned that even limited damage to nuclear infrastructure carried inherent risks.The IAEA has consistently warned that attacks on such facilities could have severe consequences for human safety, environment and regional stability, even if immediate radiation levels appeared normal.The Natanz facility, central to Iran’s uranium enrichment programme, has been targeted multiple times in the past, reflecting its strategic importance in the broader geopolitical contest over Tehran’s nuclear ambitions.Grossi emphasised that the agency was actively monitoring developments and seeking further information from Iranian authorities, while maintaining contact with inspectors on the ground.