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The US relies primarily on the Aegis system for ICBM defense, which uses the SM-3 capable of Mach 10+.

As with all things military, why have one project in a well funded area, when you can have many?!

Army - Patriot

Army / Missile Defense Agency - THAAD

Army / Air Force / Missile Defense Agency - Ground-Based Midcourse Defense w/ GMI

Navy - Aegis w/ SM-3 (also, Aegis Ashore)