Missile Defense is a term referring to systems, weapon programs, or technology involved in the defense against a missile. As an open ended term, its precise meaning has changed over the years and been modified by specialized communities. Historically, Missile Defense has been part of the Air Defense systems.
In the 1950s and 60s, the term meant defense against strategic (usually nuclear armed) missiles. The technology mostly centered around detecting offensive launch events, tracking in-bound ballistic missiles but with limited ability to actually defend against the missile.
In the late 1960s, technology had matured to the point to allow limited rudimentary missile defense by using anti-ballistic missiles. At first, these anti-ballistic missiles were armed with their own nuclear weapons, since precision technology to "hit-a-bullet-with-a-bullet" did not exist.
In the early 1980s, under the Reagan SDI program, technology had matured to consider space based missile defense options, and precision hit-to-kill systems where the anti-ballistic missile physically hits the inbound ballistic missile. The history of the program was covered under an umbrella of National Missile Defense.
In the early 1990s, the term expanded to include Theater Missile Defense , as dramatically seen in the Gulf War.
In the late 1990s, and early 2000s, the issue of defense against Cruise Missiles became more visible.
In the United States of America, the Missile Defense Agency has assumed a lead role in all phases of missile defense.
Well-known defense systems and initiatives
See also
