Iran's Nuclear Missile Delivery Capability

Recently there has been a lot of attention given to the “Possible Military Dimension” of the Iran Nuclear Program, in particular concerns over Iran’s ballistic missile program and its nuclear delivery capability.

Iran’s potential acquisition of nuclear weapons, and future ability to arm its missiles and aircraft with such weapons, represents the most serious risk shaping US, Arab, Israeli, and EU relationship with Iran. It is also an area where the exact details of threat perceptions are particularly critical, although many key aspects of Israeli, US, and Gulf perceptions – as well as the perceptions of other states – are impossible to determine at an unclassified level.

The present U.S. administration’s goal is to conclude a comprehensive agreement that would curb the Iranian program to the point that, if Iran decided to breakout and pursue the building of a nuclear bomb, it would take Iran at least a year or more to make enough fissile material for a nuclear bomb.

Estimates of the nature of Iran’s nuclear weapons efforts vary sharply, although most US, European, Gulf, and Israeli policymakers and experts now agree that Iran is actively working towards at least the capability to produce nuclear weapons. Similarly, they agree that Iran possesses virtually all the Institutional and Industrial Infrastructure plus the Technology and Equipment necessary to produce fission weapons and has significant nuclear weapons design data. There is no agreement as to exactly how far Iran has come in weapons design and “weaponization” if a dedicated program exists.

In November 2007, a report by the U.S. National Intelligence Estimate “Iran: Nuclear Intentions and Capabilities” basically concluded with the following statement: “We judge with high confidence that in fall 2003, Tehran halted its nuclear weapons program; we also assess with moderate-to-high confidence that Tehran at a minimum is keeping open the option to develop nuclear weapons.”

In November 11, 2011, the IAEA published a report claiming "credible" information that Iran had carried out activities "relevant to the development of a nuclear explosive device", the report also included intelligence indicating Iran had a nuclear weapons research program in 2003 but that senior Iranian leaders stopped it when it was discovered and came under increased international pressure.  The report identified 12 specific areas, pertaining to Nuclear Explosive Indicators:

  1. Program management structure
  2. Procurement activities
  3. Nuclear material acquisition
  4. Nuclear components for an explosive device
  5. Detonator development
  6. Initiation of high explosives and associated experiments
  7. Hydrodynamic experiments
  8. Modelling and calculations
  9. Neutron initiator
  10. Conducting a test
  11. Integration into a missile delivery vehicle
  12. Fuzing, arming and firing system

Under the IAEA-Iran Framework for Cooperation, September 2014, Iran failed to address and provide full clarification in the area of detonator development, initiation of high explosives and associated experiments, and modelling and calculations.

In a “Statement for the Record Worldwide Threat Assessment of the US Intelligence Community Senate Select Committee on Intelligence” James R. Clapper, Director of National Intelligence January 29, 2014 stated: “We do not know if Iran will eventually decide to build nuclear weapons. Tehran has made technical progress in a number of areas—including uranium enrichment, nuclear reactors, and ballistic missiles—from which it could draw if it decided to build missile-deliverable nuclear weapons. These technical advancements strengthen our assessment that Iran has the scientific, technical, and industrial capacity to eventually produce nuclear weapons. This makes the central issue its political will to do so.”

He continued to say: “We continue to assess that Iran’s overarching strategic goals of enhancing its security, prestige, and regional influence have led it to pursue capabilities to meet its civilian goals and give it the ability to build missile-deliverable nuclear weapons, if it chooses to do so.”  On Iran’s ballistic missiles he said: “We judge that Iran would choose a ballistic missile as its preferred method of delivering nuclear weapons, if Iran ever builds these weapons. Iran’s ballistic missiles are inherently capable of delivering Weapons of Mass Destruction (WMD), and Iran already has the largest inventory of ballistic missiles in the Middle East. Iran’s progress on space launch vehicles—along with its desire to deter the United States and its allies—provides Tehran with the means and motivation to develop longer-range missiles, including an intercontinental ballistic missile (ICBM).”

So the question asked by many analysts is, if Iran would most likely use its ballistic missiles as a nuclear delivery platform, then why is it not included as one of the main issues in the framework of a comprehensive deal on the nuclear program. Iran has rejected this and even went to an extent as reported by FARS News Agency Sat Aug 23, 2014 “Iran's Defense Minister Brigadier General Hossein Dehqan reiterated that any information about the country's missile industry and scientists are highly confidential and would never become a topic of talks between Tehran and the world powers. The missile issue has not been raised in the negotiations and Iran's missile power will never be an issue for negotiations with anyone.”

This report will analyze the Iranian Shahab 3/3M ballistic missiles as nuclear weapons delivery systems. In the weaponization process of nuclear devices the weight, sizes and the shape of the nuclear weapon must be compatible with the missile. These are issues that a new analysis by the Burke Chair at the CSIS addresses. This analysis is entitled Iran’s Nuclear Missile Delivery Capability, and is available on the CSIS web site at

Findings of the report:

Based on the “high technical capabilities” of the nuclear weapon states such as the U.S. and Russia, both gun-type and implosion-type devices can be made small enough to be delivered by missiles, while emerging weapon states with “low technical capability”, such as Iran, are currently unlikely to have the same technical sophistication to design compact warheads.

Based on the assumption that there is sufficient public information available on nuclear weapons, and the enrichment process that a simple low tech implosion type nuclear weapon doesn’t need testing. The design is straightforward and has been tried by a number of countries to the extent that scientists and engineers can be confident that the weapon will work without undergoing multiple testing. There is no agreement as to exactly how far Iran has come in weapons design, over the nature of its nuclear weapons program and “weaponization” if a dedicated program exists. 

The risk of proliferation of weapons of mass destruction (WMD) and their delivery systems on both horizontal proliferation (the spread of nuclear weapons to new states) and vertical proliferation (increases in the size and sophistication of nuclear arsenals within existing nuclear states) has become one of the gravest threats facing international peace and security. For a state to manufacture nuclear weapons there must be two major elements present: the capability to do so, nuclear capability, and the motivation as well as political will.

Nuclear capability”, consists of the inputs, technical know-how and resources. Resources include the needed materials for a nuclear weapon such as nuclear reactors, uranium enrichment, and the delivery means.

Motivation and political will” are based on a state’s threat perception and security concerns, consequently the political decision to acquire nuclear weapons. 

Given the political motivation, if Iran as a non-nuclear weapon state plans to build nuclear weapons, it must undergo the following technical steps:

(i) build a scientific and technological infrastructure and capability to conduct research on the design of nuclear weapons;
(ii) acquire a sufficient quantity of weapons-grade (Plutonium or Uranium) fissile material;
(iii) build a nuclear weapon device;
(iv) integrate the nuclear weapons device with a delivery system.
Steps (iii) and (iv) are referred to as the "weaponization" of nuclear devices.

The report shows that iran has the institutional and industrial infrastructure that satisfy the steps required to build a nuclear bomb and its delivery system.

The report assumes that Iran can only develop low technology 20kt yield nuclear devices (same yield as the nuclear bomb dropped over Nagasaki, Japan), with an overall warhead weight around 1000kg. Whereas for advanced nuclear states, such as the U.S., Russia, France, Israel being in that category, in the same weight of 1000kg they can build 100kt to 300kt nuclear devices. An estimate of the size of implosive fission warheads are made by modern emerging nuclear states, subsequently the warhead weights are then used to estimate the maximum deliverable ranges by the ballistic missiles.

A "nuclear capable" missile is defined by the MTCR as one with a payload capability in excess of 500 kg combined with a range in excess of 300 km. This definition is based on an assumption that an emerging nuclear state will be unable to build nuclear warheads weighing less than 500 kg.

Iran has received Soviet designed Scud-B missiles and it has adapted the design into two independently-built versions; the Shahab 1 and Shahab 2. Both of which have the same diameter of 88 cm and their ranges, for 750 kg warhead, are 340 and 440 km respectively.  For a 1000 kg warhead the ranges become 285 and 370 km. Even though the Shahab-1 could fit a 1000 kg warhead but it cannot reach deep into GCC territory. Whereas the Shahab 2 nuclear capability is marginal to deliver nuclear warhead in excess of 350 km.

Iran’s Shahab 3 & 3M missiles which have a diameter of 125 cm and a range in excess of 900 km with a payload of 1,000 kg would be able to deliver a nuclear warhead to many of the Middle East capitals and high-value targets. Comparison of the potential ranges of the Iran Shahab missiles versus the Israeli Jericho 2 missile is made. It was found that if Iran launches the Shahab-3M from the Tabriz missile site, carrying a 20kt warhead, it can potentially reach Tel Aviv. Whereas Israel, can by launching a Jericho 2 missile from the north of Israel, reach Tehran.

This could lead to two “what if” scenarios regarding the Iran nuclear program:

Iran as a Nuclear Threshold State. The presence of nuclear weapons production programs with the capability to produce one nuclear weapon (low, medium or high tech).

Iran already is in possession of a low Yield (20kt) crude nuclear weapon, and has modified its Shahab-3 ballistic missile to fit the weight, size and shape of the nuclear devise.

Regional Implications in accepting Iran as a “Nuclear State”, or as a “Nuclear Threshold State”:

Strengthen Iran as a regional power in the region leading Iran to demand that it has a say in any political and security arrangements in the Arab Gulf Region, Iraq, Afghanistan and the Middle East Peace Process.

Cause oil price shocks giving rise to further economic pressures on highly dependent industries and consumers, as well as raising geopolitical tensions, whenever the opportunity arises that serves Iran’s interests.

Increase the dangers of and arms race and weapons of mass destruction proliferation in the Middle East region.

US and GCC cooperation to defeat the Ballistic Missile threat Iran poses to the Gulf:

The only effective counter-strike capability Iran has other than asymmetric warfare in the Gulf, and the use of proxies like Hezbollah, is their ballistic missile force. A massive retaliation strike with whatever launching sites that have survived a U.S. first strike could still cause quite a considerable damage to the GCC states, on energy, finance and various other critical infrastructure centers.

The U.S. is working with its GCC allies in the Gulf to develop the capability to defeat the threat Iran poses to the Gulf, allied territory, and the flow of trade and energy exports. GCC countries worry that during a crisis, Iran could try to prevent their ships from traversing the Strait of Hormuz, cutting off their oil export business – 17 million barrels/day flows through the Straits of Hormuz, which is roughly 35% of all seaborne trader oil, or 20% of oil traded worldwide.

The U.S. is currently involved in building a defensive shield against such a massive Iranian Ballistic Missile attack targeted at the GCC states. The defensive shield consists of a Multi-Tier Ballistic Missile Defense System consisting of Terminal High Altitude Air Defense (THAAD) and Patriot Advanced Capability, PAC-3, missile systems supported with the most advanced radar and command and control facilities.

Ballistic missile defense (BMD) systems have been provided to Kuwait, the United Arab Emirates, Qatar, Oman, and in planning for Saudi Arabia, as well as stationing Aegis-equipped warships in the waters of the Arabian Gulf. The U.S. has been developing an integrated early warning radar system across the GCC states that could help U.S. and GCC forces to quickly respond to an Iranian missile attack.

GCC and Non-GCC Arab States Response:

The Arab Gulf states have been investing heavily in the modernization and upgrading of their force structures. The United States, France and United Kingdom have been the major weapons suppliers. They also recognize that the assistance of outside regional powers will be required to deal with any military aggression in the region. As a result they have signed bilateral defense agreements with their Western allies - United States, Britain and France.

Saudi Arabia is looked upon to play a pivotal role in the Security Arrangements of the Gulf and the Arab Israeli conflict. Saudi Arabia’s oil resources, population and strategic depth make it a major and essential participant in any regional security arrangements or conflict in the Gulf region.

Any realistic resolution to the Iranian nuclear program will require an approach that encompasses military, economic, political interests and differences of the West vs. Iran. There will be no lasting resolution to the Iranian nuclear program until the broader interests of Iran, the US, the GCC states and the world are addressed. Iran should be engaged directly by the U.S., with direct consultations with the GCC states, with an agenda open to all areas of military and non-military issues that both are in agreement or disagreement.

The U.S. is central to any diplomatic solution in dealing with the Iranian nuclear program, and the only country that can launch a successful military solution, if all peaceful options have been exhausted and Iran has left no other means to convince it to stop or change its course in pursuing nuclear weapons, The U.S. should alone determine what the timeline could be if Iran does pursue the path to develop nuclear weapons.

The U.S. should continue trying to make diplomacy and engagement the priority in dealing with the Iranian nuclear program, and will have to try to make comprehensive verification of Iran’s nuclear development program as one of the priorities in any diplomatic dialogue, while trying at the same time to persuade Iran to stop its enrichment program and to cooperate and answer to all enquiries of the IAEA to the possible military dimensions of the IAEA Director General’s Report.

Nuclear Exchange between Israel and Iran:

The report presents a brief description of the major civilian effects if a nuclear conflict between Iran and Israel takes place in the future, assuming by then that Iran has a fully operational nuclear weapons capability, and the possible broader impact on other countries in the Middle East such as Jordan and Damascus. Threat perceptions and security concerns between Israel and Iran could reach to a critical point that a nuclear exchange becomes inevitable, even if limited in nature.

Nuclear warheads have long been targeted at population centers in addition to military targets, with the primary purpose of destroying an entire city with just one or two nuclear weapons. Actual damages are likely to be greater than that calculated in this study, due to indirect effects such as deaths resulting from injuries and the unavailability of medical attention and facilities.

Conventional Unitary Warheads on the Shahab-3 missile:

The report looks into the effectiveness of the Iranian Shahab-3 missile, to inflict damage, when fitted with a conventional unitary high explosive warhead. Iran’s ballistic missiles, operational and under development, cover the complete spectrum range from150 km up to 5,500 km, the short, medium, and intermediate ranges.  Iran believes that ballistic missiles will compensate for any deficiencies in its air power.

Deploying Ballistic Missiles against military targets would require a number that is very likely to be beyond the current Inventory in Iran. Presently the Shahab Missile is known to have a CEP (Circular Error Probability) greater than 500m, which is large compared to the lethal radius of hardened structures, a large number of missiles with unitary warheads will be required to ensure destruction of such targets. For example a psi of 40 is required to damage a reinforced command center, with a 1000 kg TNT explosive weight the weapon, lethal radius is 21 meters. For a required damage of 0.75 the number of missiles required, if the CEP of the missile is 500 meter, is 1,286.

However, if the missiles are used against large military bases and installations, even with missiles that have large CEPs they are likely to hit something or at least cause some form of damage and disrupt activities. Ballistic missiles can also be used with success against soft targets, in open areas and cities to inflict maximum human casualties and create terror. In essence what is considered as a major component in asymmetric warfare in the form of high civilian casualties.

Options and Risks in Dealing with Iran’s Nuclear Program:

The issue of Iran’s nuclear program is complex and bears lasting global consequences if not approached with adequate knowledge and awareness, particularly so if not taking the high risk tracks involved into consideration. The threat is perfectly understood: all are in agreement that Iran as a nuclear threshold state or a nuclear state, will be unacceptable to the security and stability of the region. The last thing this region needs is becoming more a part of the global arms race or the heightened dangers of more weapons of mass destruction proliferation, especially within the so far relatively stable GCC region that remains the global hydrocarbon reserve and has attained impressive and model levels of socio-economic development and globalization.

GCC states are clear in their “End Game” approach, which is based on a clear statement of the final aims in stopping Iran from building nuclear weapons and their delivery systems. The next step should be a clear outline of the strategic policies that should be adopted to achieve the aims, while keeping the risks associated with the consequences of each strategic policy option to a minimum.

The concern is that such a clear “end game” approach might in the P5+1 negotiations with Iran turn into a “process approach” in which an open ended dialog, talking for the sake of talking, until a light at the end of the tunnel is seen, that will guide the parties to the next step. The risk perceived is that Iran just wants to exploit an open-ended dialogue to buy time and alleviate the pressure of sanctions, with no intent to terminate any of its nuclear activities.

The current P5+1 negotiations with Iran points to the direction of adopting dialogue and diplomacy, sanctions, deterrence and active defense, carefully balancing the timing, duration, and level of intensity of implementation in each phase of trying to defuse the crisis with Iran, and inducing Iran to abide with all international agreements and to cooperate fully with the IAEA. With regards to a military strike, it should be made clear that it remains on the table as an option of “last resort”, if all else fails.

It should be strongly emphasized that the U.S. must put all its weight in not allowing any unilateral military strikes by Israel that can definitely push the presently volatile Middle East region into a war with far reaching global consequences and a high end price for Israel itself. The issue has become an existential threat for the entire region rather than any one country alone.

In addition to the options in front of the P5+1, diplomacy, dialogue and economic incentives; sanctions; extended deterrence and active defense; preventive or preemptive strikes before Iran has a significant nuclear force, the report recommends that an Arms Control and Regional Security negotiations process to take place in the immediate future.

A Recommended Arms Control and Regional Security process in the region with Israel and Iran participating, leading to a Nuclear Weapons Free Zone in the Region.

Both James R. Clapper, Director of National Intelligence, and Gen. Martin E. Dempsey, the Chairman of the U.S. Joint Chiefs of Staff emphasized that the central issue is Iran’s political will to pursue nuclear weapons. General Dempsey stated “using the military instrument of power simply would delay Iran's nuclear ambition, as opposed to eliminating it. He concluded by saying “It would be a "much wiser course" for Iran to go the diplomatic route”.

The political and diplomatic route would include an arms control process, on a bilateral basis and a multilateral level, such as the M.E. Arms Control and Regional Security (ACRS), be proposed to start as soon as possible. Iran was not invited to participate in the ACRS process of the 90s. A lot of groundwork was covered and it should not be difficult to reintroduce the areas and concepts that the Arab Countries negotiated with Israel. Iran can certainly benefit from all this past work and join in the negotiations as a principal participant.

This process can start addressing Confidence and Security Building Measures (CSBMs) in both political-military and technical-military areas. Military-to-military talks and negotiations need to address military doctrines, defense postures, threat perceptions and security concerns. The United States with the international community should encourage and provide support to regional countries interested in establishing Weapons of Mass Destruction Free Zones (WMDFZ), based on the zone that has been proposed in the Middle East.

These measures can create an atmosphere and an environment that can induce disputing parties to negotiate in a less threatening environment and can remove misunderstandings and surprises. One recent example is for countries to adopt the “International Code of Conduct against Ballistic Missiles Proliferation”. This constructive engagement should take place between regional parties under a regional institutional framework.

International arms control regimes and treaties should be strengthened. Countries need to sign and ratify the NPT, CWC and the BWC, as well as strengthening the verification and monitoring procedures that follow. Other agreements such as the Missile Technology Control Regime (MTCR), Comprehensive Test ban Treaty (CTBT) and Fissile Material Cut-Off should also be adhered to by all states and should be applied as a law in the respective countries.


This report will be updated and expand in the future, and any additional material and comments would be greatly appreciated. Please send such comments and material to Antony H. Cordesman at and


Anthony H. Cordesman

Anthony H. Cordesman

Former Emeritus Chair in Strategy

Abdullah Toukan