Faced with an increasingly formidable anti-ship cruise missile threat from the Soviet Union in the early days of the Cold War, and with the recent memory of the kamikaze threat from World War II, the USN placed a great priority on developing air defence cruise missiles and getting them to sea to protect the fleet. The first of these missiles were sizable, necessitating large ships to carry them and their sensors, which resulted in the conversion of a mix of heavy and light cruisers. These ships, tasked with protecting carrier groups and acting as flagships, entered service from 1955 and served until 1980.