Missile Nonproliferation and Missile Defense: Fitting Them Together

Richard Speier

Missile nonproliferation and missile defense are directed against the same threats. Each seeks to prevent damage from proliferators’ missiles, one by acting before launch and the other after launch.[1] For good reason, the United States has been pursuing both approaches. Nonetheless, in practice there are gaps and potential conflicts between nonproliferation and defense strategies.[2]

To bolster U.S. and global security, the United States should lead efforts to meld these two approaches better. In particular, the United States should seek to restrict the export of countermeasures that could make it easier to penetrate missile defenses.The United States also should tightly restrain the export of large interceptors, such as those used in its ground-based midcourse defense system, and ensure that such interceptors remain under U.S. command and control.

Missile Nonproliferation

Missile nonproliferation is a widely accepted instrument of international security. Thirty-four governments participate in the Missile Technology Control Regime’s (MTCR) export control policies and associated measures. Other governments, including China and Israel, profess to adhere to the MTCR’s guidelines. Although the MTCR is directed against the proliferation of ballistic and cruise missiles that exceed certain parameters, the current issues pertaining to missile defense concern ballistic missiles and this paper will focus on them.

The MTCR’s key provision draws a line between items for which there is a strong presumption to deny export (Category I) and those that may be exported on a case-by-case basis (Category II). The heart of the MTCR is a set of stringent restrictions on the exports of Category I items, details of which are included in the MTCR’s Annex. These items include missiles (Item 1) and major subsystems (Item 2).[3]

Item 1 is comprised of “complete rocket systems (including ballistic missile systems, space launch vehicles, and sounding rockets)...[and] complete unmanned aerial vehicle systems (including cruise missile systems, target drones, and reconnaissance drones)...capable of delivering at least a 500[-kilogram] payload to a range of at least 300 [kilometers].” These parameters were selected because 500 kilograms is the mass of a relatively unsophisticated nuclear weapon, and 300 kilometers is the strategic distance in the most compact theaters in which nuclear weapons were deemed likely to be used.

Item 2 is comprised of major subsystems for Item 1 systems, such as individual rocket stages, re-entry vehicles, rocket motors and engines, guidance sets, and control and warhead subsystems. The rest of the Annex is a detailed list of 18 additional Category II items that may have permissible uses and may be exported after review.

The Countermeasures Threat

Ballistic missile defense is increasingly accepted as an instrument of international security. Japan, NATO members, Russia, the United States, and others are developing, acquiring, and in some instances exporting missile defense systems to protect against threats of various ranges.

President George W. Bush’s December 2002 National Security Presidential Directive (NSPD)-23 stated, “The goal of the [MTCR] is to help reduce the global missile threat by curbing the flow of missiles and related technology to proliferators. The MTCR and missile defenses play complementary roles in countering the global missile threat.” To elaborate on Bush’s words, missile defenses, if perceived as being effective, can complement the MTCR by making offensive investments unproductive and thereby discouraging the acquisition of missiles in the first place. The MTCR, by reducing the spread of missiles, can reduce the stresses on missile defenses.

The effectiveness of the MTCR in this respect is hampered by its failure to include limits on the export of countermeasures, which are devices intended to defeat missile defenses. They are also known as penetration aids or penaids. China, Russia, the United Kingdom, and the United States are known to have relatively effective countermeasures in hand or under development. In general, penaids use three techniques:

Saturation, presenting a large number of targets for defensive interceptors, as with submunitions;

Concealment, obscuring a re-entry vehicle (RV), as with signature reduction or jammers, or mixing the RV with other objects, as with chaff or decoys; and

Evasion, maneuvering the RV to avoid interception, as with terminal guidance and aerodynamic controls.

The proliferation of effective penaids to additional states would exacerbate a number of threats to international security:

1) It would increase the problem of missile proliferation. By offering the prospect that missiles can penetrate defenses, penaid proliferation encourages missile proliferators to devote more resources to their offensive programs. The result may be a greater number of more sophisticated offensive missiles.

2) It would reduce crisis stability. Penaid proliferation, if it diminishes the effectiveness of missile defenses, may increase the incentive for the defender to strike an opponent’s missiles before they are launched. Moreover, some of the technologies of penaid proliferation involve the deployment in space of multiple objects controlled with respect to position and velocity. These technologies contribute to the capability of delivering multiple warheads from a single missile. It is accepted arms control doctrine that multiple warheads further increase the incentives for a pre-emptive disarming strike by enabling one warhead to destroy several warheads, creating a “use it or lose it” incentive to strike first in a crisis.

3) It would complicate deterrence. The continued reduction of U.S. and Russian strategic nuclear forces is a major international objective. Such reductions become complicated if, at the same time, the gap is unexpectedly narrowed between these major powers and proliferators. The gap would indeed be narrowed if proliferators increased the numbers and sophistication of their missiles.

4) It would stress missile defenses. To the extent that defenses are challenged by penaids, the defenses must be made more sophisticated and expensive. This is particularly true for defenses in Europe and Asia. The exoatmospheric flight time for a 2,000-kilometer-range offensive missile is about one-half of the flight time for a 6,000-kilometer-range missile. This gives less time to discriminate warheads in the presence of concealment measures.

The export of countermeasures against missile defenses are not controlled by the MTCR, with a few exceptions. At present, the proliferation of most penaids is perfectly legal.

The Feasibility of Controls

The international community can take measures to constrain penaid proliferation. Just as with missile proliferation itself, penaid proliferation can be hindered by export controls.

Missiles are complex systems. Less advanced countries that have undertaken the development of missiles have relied on assistance from more technically advanced countries to achieve reliability and performance. The addition of countermeasures to a missile would be as exacting as any other major improvements to the basic missile and would necessitate similar help.

Some countermeasures may seem relatively simple. Measures such as booster fragmentation and the uncontrolled dispensing of simple balloon decoys have been anticipated by the U.S. intelligence community.[4] Missile defense systems with sensors operating in multiple wavelengths and locations, sophisticated kill vehicles, and interception algorithms are already being designed to cope with such rudimentary penaids.

To place stress on a modern missile defense system, penaids must be more complex. They must meet the following four criteria:

1) Penaids must be matched to the defense system they are intended to penetrate. This requires a great deal of knowledge of the defense system, including the signatures that the RV and the penaids will display to the defense. For modern missile defense systems, with multiple netted sensors, an attacker will have to determine many appropriate signatures for effective decoys. The attacker would also have to anticipate that some attempts to alter these signatures may provide other clues to the defenses.

2) Penaids must be integrated with the offensive system. Decoys must be matched to the RV that they are intended to simulate. The design of penaids in shape, volume, and weight must be payload specific to enable them to be incorporated in a missile without sacrificing so much damage capability that the system becomes ineffective. Bringing several subsystems together so that they operate adequately is a complex operation involving system engineering. This necessitates repetitive testing of the total system and subsequent modification of the participating subsystems to ensure that the final product works properly.

3) Penaids must function in space. Few missile proliferators have successfully placed a satellite in orbit. Yet, midcourse penaids must function in a zero-gravity, exoatmospheric environment. They must be ejected, erected, and operated in flight.[5] Their trajectory and flight characteristics must match those of the RV so that they give the appearance of credible threats to the defense. This means that they must be deployed to specific positions relative to the threat cloud, and they must hold these positions in flight. Position, velocity, and angular velocity in three axes all may need to be controlled. In doing this, the penaids must not interfere with the intended function of the RV. All these operations must be timed and sequenced so as not to reveal information to the defense that will assist in interceptions. Penaids intended to operate in the terminal phase of flight are confronted with even more complexities. It is easy to make disastrous mistakes in penaid system design.[6]

4) Penaids must be flight-tested. There is no way to fully anticipate operational problems and unwelcome signatures without using specially designed capabilities, extending from ground test facilities to well instrumented test ranges. Test ranges should simulate the sensor capabilities of the missile defense, which means that they will be expensive. Few missile proliferators possess such ranges. Although computer simulation and ground testing will be helpful, the ejection and performance of penaid systems cannot finally be established without major flight trials. The catch-22 is that the flight testing of penaids, if not conducted by a sophisticated country, raises the possibility that the test will be observed by the defense, making it easier for the defense to prepare counter-countermeasures.

All of these criteria suggest the importance of external assistance for penaid development. Therefore, export controls could prove useful in slowing penaid proliferation. Recommended additions to the MTCR’s control list are shown on the next page.

Missile Defense

Export controls on countermeasures would complement the purposes of the MTCR and missile defenses. Missile defense, with its growing variety of large interceptor rockets, can also compete with the MTCR because some missile defense interceptor rockets exceed the MTCR’s 500-kilogram/300-kilometer line. Exporting them weakens the MTCR’s central restraint by inviting other MTCR partners to make their own Category I exports. These exports can directly contribute to proliferation, if diverted, because missile defense rockets and their technology are interchangeable with offensive rockets.

Most of the systems now in use or in advanced development, such as the Patriot, the U.S./European Medium Extended Air Defense system, most versions of the Russian S-300, and the Theater High Altitude Area Defense system, fall below the MTCR’s “strong presumption to deny” threshold.

Other missile defense interceptors exceed the MTCR threshold. The U.S. SM-3 interceptor, recently described as under “close collaboration” with Japan,[7] slightly exceeds the threshold. The Israeli Arrow not only exceeds the threshold but has been used as a target missile in an offensive configuration. The ground-based interceptors, now deployed in Alaska and California and in the future possibly in Europe, and the Kinetic Energy Interceptor, in development, greatly exceed the MTCR threshold. These rocket systems can serve as the basis for offensive missiles, as the Soviet air defense SA-2 missile has served in China, India, Iran, Iraq, and Serbia. Nonetheless, the Bush administration favors missile defense cooperation with U.S. allies. For that reason, it stated in NSPD-23 that the United States should administer the MTCR so that it does not impede missile defense cooperation.

Yet, certain circumstances mitigate the likelihood that large interceptors will be exported. For one, some advanced proposals for missile defense systems, such as laser and space-based concepts, would not require the export of large interceptors. Also, when the export of large interceptors is being considered, many other barriers exist besides the MTCR.

The “family jewels” of missile defense are not the rockets themselves. Rather, they are the more advanced technology embodied in such items as radars, flight-based sensors, and discrimination and interception algorithms. Given that exporting these items may jeopardize the security of their technology, there will be a natural caution about exporting advanced missile defense systems, without reference to the MTCR.

Moreover, missile defense operates far better when all of the components, including radars, sensors, interceptors, and decisions, are under unified command and control. As long as an ally is being defended by U.S. missile defenses, it is unnecessary and even counterproductive for the ally to have access to large interceptors. One site with ground-based interceptors can defend almost all of Europe. It is not necessary for every ally, or even one, to gain access to the system. Although missile defense installations may be sited on foreign territory, as long as the interceptor rockets remain under U.S. jurisdiction and control, the MTCR does not consider them to have been exported.

To be sure, the MTCR guidelines allow “rare” exports of Category I items. Such transfers are subject to stringent conditions, including a requirement that the supplier and not just the recipient be responsible for the end use. Unified command and control would help meet this criterion and might eliminate the need for an “export.” In the case of NATO, in which military cooperation is based on the North Atlantic Treaty, there is a general rule of international law that a policy, such as the MTCR, cannot supersede a treaty. Therefore, missile defense shared as part of NATO programs is exempted from the MTCR guidelines in principle. Nonetheless, it would weaken the MTCR’s restraint if large interceptors were exported helter-skelter to NATO partners. The value of unified command and control still weighs in favor of keeping such interceptors under U.S. control.

Centralized control, rather than exports, of large interceptors makes good sense in terms of military and nonproliferation considerations. Missile defense need not lead to the wide proliferation of Category I systems. The key for missile defense policymakers is to avoid demonizing the MTCR and to look more broadly at export vulnerabilities and operational realities.


Missile nonproliferation and missile defenses can help each other in new ways. The next steps are to control exports of countermeasures and to be more realistic about exports of large interceptors. The results should be more effective missile defenses and less missile proliferation.

Additions to the Missile Technology Control Regime

The Missile Technology Control Regime (MTCR) needs to be strengthened to restrict the export of countermeasures to missile defenses. In order to do so, changes need to be made to the list of heavily restricted items under Category I of the MTCR and to items subject to a case-by-case review under Category II. Below are some illustrative additions.

Category I

These changes would apply to Item 2 of the MTCR Annex, dealing with complete subsystems and their technology usable in unmanned systems capable of delivering a 500-kilogram payload to a range of 300 kilometers.

Additions to Annex Item 2 should restrict countermeasure subsystems and penetration aids designed to saturate, confuse, or evade missile defenses, including:

1. Complete physical or electronic countermeasure suites.

2. Complete penetration-aid canisters, dispenser subsystems or interstages for these subsystems, which contain and dispense penetration aids and connect them to the missile.

3. Post-boost vehicles, which aim the re-entry vehicles and penetration aids.

4. Re-entry vehicle replicas or decoys.

5. Re-entry wake modification mechanisms, which disguise the signature of a re-entry vehicle as it re-enters the atmosphere.

6. Submunitions specially designed for the delivery of liquids, gases, or powders.

7. Test results, fly-along sensor packages, or specially designed test facilities for items 1-6.

Category II

Other proposed additions would adapt existing Category II items in the MTCR Annex. They would be placed in Category II, case-by-case export control review, because they also have other uses that should not necessarily be restricted, including use with satellites, for the protection of satellites from anti-satellite weapons, and in missile defenses themselves.

The adapted items would add restrictions to controls on instrumentation, flight control, avionics, launch support, computers, test equipment, modeling-simulation and design integration, stealth, and nuclear hardening, including:

1. Items, other than post-boost vehicles, which would be covered in Category I, for the automatic or remotely controlled deployment of flight objects in space. An example is spin-eject/tipoff control mechanisms. These control motions such as spin and tumbling in re-entry vehicles and penetration aids.

2. Items for the automatic or remotely controlled erection of inflatable or variable-geometry objects in space, which control the inflation of balloons and the opening in space of other penetration aids.

3. Items to confuse the observation of re-entry vehicles or spacecraft, including:

• Space-qualified radio frequency or infrared countermeasures equipment, which include such devices as emitting decoys or jammers.

• Space-qualified aerosols, chaff, or flares, which are “trash” intended to create large volumes of distracting or opaque images.

• Antisimulation devices, which are devices designed to make a re-entry vehicle look like a decoy or decoys.

• Plasma shield modification mechanisms, which control the electromagnetic noise around a re-entering object, including peaceful spacecraft.

4. Items for hardening against thermal pulses from nuclear detonation. The MTCR already covers hardening against nuclear radiation pulses.

5. Test results and test and diagnostic equipment for such items.

6. Software specially designed for the development and testing of such items.

7. Sensor subsystems of missile defense systems.

Richard Speier is a private consultant on nonproliferation and counterproliferation issues. He spent more than 25 years in government at the Office of Management and Budget, the Arms Control and Disarmament Agency, and the Office of the Secretary of Defense, during which he helped negotiate the Missile Technology Control Regime.


1. Some of the concepts in this paper were extensively influenced by two colleagues: K. Scott McMahon, who has published many analyses of missile defenses, and Stanley Orman, who managed the British development of countermeasures against Soviet missile defenses. The views in this article are the writer’s own.

2. See Richard Speier, “Complementary or Competitive? Missile Controls vs. Missile Defense,” Arms Control Today, June 2004, pp. 20-21.

3. For documents related to the MTCR, see http://www.mtcr.info. A great deal of misinformation has resulted from scholars and government officials reading only the MTCR’s Guidelines and not its Annex. The MTCR addresses not only ballistic missiles but also cruise missiles and space launch vehicles.

4. Robert D. Walpole, “Foreign Missile Developments and the Ballistic Missile Threat to the United States Through 2015,” Statement to the Senate Foreign Relations Committee, September 16, 1999; Amy Butler, “MDA Adds Countermeasures to GMD Test,” Aviation Week & Space Technology, October 8, 2007, p. 32

5. These are not trivial tasks. On July 7, 2000, a simple balloon decoy failed to inflate as part of a widely watched U.S. missile defense test.

6. Using the laws of physics, a group of American scientists designed “simple...effective” countermeasures that they believed would penetrate missile defenses without the necessity for flight tests. Union of Concerned Scientists, “Countermeasures,” April 2000. Analysis revealed that these approaches would be neither simple nor effective. See Defense News, June 19, 2000, p. 19; Defense News, July 10, 2000, p. 15; Defense News, July 24, 2000, p. 36.

7. “Japanese Official Warns of Chinese Missile Threat,” Global Security Newswire, July 16, 2007.