The world is an unsettled place, with a bellicose North Korea, with China rapidly developing advanced military capabilities, with an aggressive Russia apparently determined to reconstruct the Soviet Union and with unrest in the Middle East. Add into the mix the proliferation of ballistic missile technology -- much of it exported from North Korea -- and you have a potential for disaster. In fact, U.S. Navy destroyers have shot down several short- or medium-range ballistic missiles fired from Yemen in recent days.
The Pentagon's Missile Defense Agency oversees U.S. missile defenses and cooperates with a number of allies to minimize the danger. Here's an overview:
-- The first problem in defending against ballistic missile is detecting the launch of a threat missile. This is an intelligence effort, as well as warning from space-based sensors.
-- The U.S. Missile Defense Agency has a number of long-range radars to detect incoming missiles. One fixed site (Cobra Dane) is in the Aleutians at Shemya (Photo). Another is a large sea-based X-band radar on a self-propelled oil drilling-like platform that is normally active in the Pacific (Photo). Others are strategically placed around the world.
-- The U.S. has 44 ground-based interceptors based in Alaska and California. (Photo)
-- The U.S. Navy has 30+ cruisers and destroyers with advanced AEGIS radar systems and armed with RIM-161 Standard SM-3 missiles that can intercept shorter-range and some intercontinental ballistic missiles. These are on watch in the Western Pacific and based in Rota, Spain. The same shipboard systems have been installed ashore in Poland and Romania (Photo) to protect NATO allies. Japanese destroyers also use this system and South Korea and the Netherlands are adopting it as well.
-- The Army has THAAD (terminal high altitude area defense) missile batteries in a number of locations (Photo), including the relatively vulnerable island of Guam in the Pacific. One THAAD battery is in South Korea.
-- The Army also has MIM-104 Patriot missile batteries that are highly mobile; these are less capable than the above systems but still useful. They have been provided to a number of allies as well and have been promised to Ukraine (Photo).
Tests have shown that virtually none of these systems is 100% effective at destroying incoming missiles, but firing multiple interceptors at a threat works well. Still, when dealing with a nuclear or chemical/biological warfare threat, it only takes one getting through the defensive umbrella to cause disaster.
https://en.wikipedia.org/wiki/NATO_m...defense_system