Constraining Iran's Missile Capabilities

March 28, 2019

Weapon Program: 

  • Missile


Robert Einhorn and Vann H. Van Diepen


The Brookings Institution


For decades, the United States has sought to constrain Iran’s missile program, both because it poses a conventional military threat to regional stability and because it can provide a delivery capability for nuclear weapons should Iran acquire them. But despite the efforts of the United States and others to impede Iranian procurement of missilerelated materials, equipment, and technology and a succession of U.N. Security Council (UNSC) restrictions imposed largely to prevent Iran from acquiring nuclear weapons delivery systems, Iran has managed to acquire the largest and most diverse missile force in the Middle East.

The Iranian missile threat

Relying initially on missiles, components, and technology purchased mainly from North Korea and China, but increasingly making advances through indigenous efforts, Iran maintains a force of hundreds of liquid- and solid-propellant short- and medium-range ballistic missiles (SRBMs and MRBMs), now being augmented by land-attack cruise missiles. Although claiming to limit itself to ballistic missiles with a 2000 km range by order of the supreme leader and not yet launching ballistic missiles above that range, Iran pursues at least four paths that it could use to develop intercontinental ballistic missiles (ICBMs) capable of reaching the United States, including the development of space-launch vehicles (SLVs) based on technologies directly applicable to long-range ballistic missiles. While placing priority on indigenous development, Iran remains dependent on importing key components and materials. It is working on more accurate guidance systems to improve the military utility of its missiles and has fielded road-mobile missile launchers to promote their survivability against attack. 

The Iranians see their missile force as an integral and indispensable part of their national defense strategy, fulfilling key strike roles traditionally taken by manned aircraft, but beyond the capabilities of an Iranian air force hobbled by many years of sanctions. The missile program serves key Iranian goals: deterring attacks against Iran, providing warfighting capabilities if deterrence fails or Iran decides to initiate hostilities, supporting military capabilities of regional proxies such as Hezbollah and the Houthis, enhancing national pride and regional influence, and providing a nuclear delivery hedge if Iran decides to acquire nuclear weapons. The use of Iranian ballistic missiles is not just theoretical. Iran has fired ballistic missiles against Iraq during the Iraq-Iran war and against various non-state actor adversaries in neighboring states in recent years. Moreover, Iranian proxies have fired Iranian-supplied missiles and rockets at U.S. regional partners Israel, Saudi Arabia, and the United Arab Emirates (UAE).

Iran’s missile program poses a serious threat to the security interests of the United States and its partners, both in the Middle East and beyond. Key U.S. objectives with respect to that program are to deter attacks and intimidation against the United States and its friends, impede quantitative and qualitative improvement in the regional missile capabilities of Iran and its proxies, maintain military capabilities that can degrade the ability of the missile forces of Iran and its proxies to achieve their objectives, and discourage and delay the development of missile capabilities that can reach beyond the region, including to Western Europe and the U.S. homeland.