Aegis Combat System
In addition to the guns that destroyers have, a guided-missile destroyer is usually equipped with two large missile magazines, usually in vertical-launch cells. Some guided-missile destroyers contain powerful radar systems, such as the United States’ Aegis Combat System, and may be adopted for use in an anti-missile or ballistic-missile defense role. This is especially true of navies that no longer operate cruisers, as other vessels must be adopted to fill in the gap.