An open question is whether Iran’s solid-propellant capability will be shared with North Korea and others in the way that liquid-propellant technology has flowed in the other direction. In this study, the committee has tried to look at the broad spectrum of threats, current or that may emerge over several years, rather than parsing the details of shifting projections of specific programs. While there is uncertainty as to the pace of either state’s progress, prudence dictates that the United States assume, in the absence of verifiable evidence to the contrary, that both North Korea and Iran will eventually have ballistic missiles capable of reaching CONUS with nuclear weapons, and that both will attempt to adapt their programs to offset U.S. defense efforts. Generic but representative examples of potential ballistic missiles, available in the open literature, and actual threat assessments from the intelligence community are provided in classified Appendix F, which accompanies this unclassified report.5
The principal hurdles in developing a true ICBM for Iran and North Korea to overcome are achieving reliability and a sufficient range, developing a workable RV, and producing a nuclear (or conceivably chemical or biological) weapon that can be used in an ICBM RV. Estimates of how long it will be before either country first tests an ICBM vary greatly, from a few months to a decade or more. Of course, a first test, even if successful—North Korea’s initial tests of a Taepo Dong 2 nominally for space launch failed—would not be equivalent to deploying an operational system, which could take additional years. Nor is it clear how soon either country could develop a workable RV and nuclear warhead for their missiles. However, the consensus of the intelligence community is that both countries could have an operational ICBM capability within a decade.
Based on the information presented to the committee, it appears any ICBM that Iran or North Korea could deploy initially would be relatively unsophisticated. However, the U.S. intelligence community expects that most of the countries that are developing ballistic missiles will improve their capabilities over time. In addition to their indigenous technological capacity, Iran and North Korea—and others seeking ballistic missile capability—are likely to be able to tap into one another’s technologies and the technologies of other missile-possessing countries, whether with those countries’ consent or otherwise.
In addition to increasing survivability and effectiveness of their ballistic missile force by measures such as mobile basing and increased accuracy, emerging ballistic missile states will likely make other improvements of significance for U.S. missile defense efforts, notably the adoption of solid-propellant systems, more energetic missiles, and the development and integration of countermeasures against missile defense systems. So far the countermeasure efforts of both appear to be directed against theater-level terminal defenses, but some—such as multiple near-simultaneous launches, which both Iran and North Korea have
5Some believe theater ballistic missiles launched by ships is a serious threat, particularly for nonstate actors, and there may be potential responses that would involve intercepting missiles.