The U.S. Navy’s Aegis Combat System has evolved considerably since the first Aegis ship deployed in 1984. Some 90 Aegis ships are currently operated by the United States, and five other countries have Aegis ships as well: Australia, Norway, South Korea, Spain, and Japan. The word “Aegis” refers to the shield of the ancient god Zeus, and Aegis ships have long provided fleet air defense, strike, and antisubmarine warfare. Over the past decade, 35 American and 4 Japanese Aegis ships have also acquired a ballistic missile defense mission. The most recent configurations are capable of executing the integrated air and missile defense (IAMD) mission, with simultaneous air defense and ballistic missile defense operations.
Some 90 Aegis ships are currently operated by the United States, and five other countries have Aegis ships as well: Australia, Norway, South Korea, Spain, and Japan . Over the past decade, 35 American and 4 Japanese Aegis ships have also acquired a ballistic missile defense mission.