How Iran’s Khorramshahr-4 missile could play a key role as US tensions rise

Iran has showcased the Khorramshahr-4 ballistic missile at a newly unveiled underground military facility, according to Iran’s Fars News Agency, which is closely linked to the Islamic Revolutionary Guard Corps (IRGC).The report said the long-range missile, with an estimated range of about 2,000 kilometres and a warhead capable of carrying more than one tonne of high explosives, was among the operational assets displayed during the site’s inauguration. Fars described the Khorramshahr-4 as one of Iran’s more advanced medium, to long-range ballistic missiles. The missile was reportedly used during last June’s 12-day conflict, when Iran launched it toward Israel following US strikes on Iranian nuclear-related targets.Iran’s Khorramshahr or the Kheibar ballistic missile is a liquid-fuelled system measuring about 13 metres in length, with a diameter of roughly 1.5 metres and a launch weight of around 20 tonnes. Its structure includes a payload compartment housing the warhead, upper and lower oxidiser tanks, an intertank section, and a fuel tank.The missile does not use grid fins; instead, its guidance equipment is housed in separate compartments located above the fuel and oxidiser tanks, reflecting a relatively simple but robust design architecture.The Khorramshahr is reportedly derived from North Korea’s Hwasong-10 intermediate-range ballistic missile, which itself is based on the Soviet-era R-27 submarine-launched ballistic missile design. According to US-based think tanks, the Hwasong-10—also known as the Musudan—was transferred to Iran in the mid-2000s, forming the technological basis for Tehran’s Khorramshahr programme.The ballistic missile features an advanced guidance and control system designed to manoeuvre and adjust its trajectory beyond Earth’s atmosphere. The system reportedly shuts down guidance mechanisms during re-entry, a measure intended to reduce vulnerability to electronic warfare countermeasures.The missile’s control architecture also removes the need for conventional slender-wing structures on the warhead, allowing it to carry a larger explosive payload compared with earlier designs.Iranian claims indicate the Kheibar has an impact endurance of about 280 seconds in ground conditions and 300 seconds in vacuum. Tensions between the United States and Iran have escalated in recent months over Tehran’s nuclear programme and regional security concerns. The US has imposed fresh sanctions targeting Iran’s defence and missile development sectors, while Washington has warned against further ballistic missile tests and military escalation. Iran, in turn, has criticised US military presence in the region and reiterated that its missile programme is defensive in nature.