The primary mission of National Missile Defense is defense of the United States (all 50 states) against a threat of a limited strategic ballistic missile attack from a rogue nation. Such a system would also provide some capability against a small accidental or unauthorized launch of strategic ballistic missiles from more nuclear capable states. The means to accomplish the NMD mission are as follows:
- Field an NMD system that meets the ballistic missile threat at the time of a deployment decision.
- Detect the launch of enemy ballistic missile(s) and track.
- Continue tracking of ballistic missile(s) using ground based radars.
- Engage and destroy the ballistic missile warhead above the earth’s atmosphere by force of impact.
The National Missile Defense Program was originally a technology development effort. In 1996, at the direction of the Secretary of Defense, NMD was designated a Major Defense Acquisition Program and transitioned to an acquisition effort. Concurrently, BMDO was tasked with developing a deployable system within three years. This three-year development period culminated in 2000, and the Department of Defense began a Deployment Readiness Review in June 2000. Using that review, President Clinton was to make a deployment decision based on four criteria: the potential ICBM threat to the United States; the technical readiness of the NMD system; the projected cost of the NMD system; and potential environmental impact of the NMD system. Rather than make a decision, President Clinton deferred the deployment decision to his successor. The White House in choosing this action cited several factos. Among them were the lack of test under realistic conditions, the absence of testing of the booster rocket, and lingering questions over the system's ability to deal with countermeasures. The deployment decision now rests with President George W. Bush, who is reexamining the Clinton NMD system along with a variety of other proposals. In the meantime, work is continuing on technology development for the NMD system.
The NMD system would be a fixed, land-based, non-nuclear missile defense system with a space-based detection system, consisting of five elements:
All elements of the NMD system would work together to respond to a ballistic missile directed against the United States.
- Ground Based Interceptors (GBIs)
- Battle Management, Command, Control, and Communications (BMC3), which includes:
- Battle Management, Command, and Control (BMC2), and
- In-Flight Interceptor Communications System (IFICS)
- X-Band Radars (XBRs)
- Upgraded Early Warning Radar (UEWR)
- Defense Support Program satellites/Space-Based Infrared System (SBIRS)