 The United States has also assigned most of its ballistic missile defense capable ships to the Pacific, extended the BMD program to all Aegis destroyers and increased procurement of SM-3 BMD missiles.The United States also has a large network optimized for tracking ballistic missile launches which may give carrier groups sufficient warning in order to move away from the target area while the missile is in flight.Kinetic defenses against the DF-21D would be difficult.