A cruise missile is an unmanned aircraft that delivers an explosive, which only flies through air. Unlike the ballistic missiles, these have the capability to fly almost like an aircraft through most of its flight and hit a specific target with accuracy.

A cruise missile is primarily made up of its airframe, propulsion, guidance, control, navigation and the explosive.

Guided missiles have emerged as a key battlefield weapon during the Cold War when both the US and the Soviet Union developed their own cruise missiles that were capable of avoiding enemy radars and taking an explosive load to a specific target such as a ship.

The modern story of these 'guided flying bombs' started sometime in the 1920s when Great Britain developed the Long Range Gun with Lynx Engine. By early 1930s the Soviets had developed their own GIRD-06 cruise missile. But it was during the World War II that the Germans showed how effective they could be. Their V-1, with a gyroscopic guidance system and propelled by a pulse-jet engine, proved deadly for many rival cities. But the potential of a 'flying bomb' with accurate guidance was brought home with deadly impact by the Japanese kamikazes, aircraft with fuel tanks, bombs etc flown into a target by pilots. The suicide missions were an act of desperation by a floundering Japanese empire in 1944, but it convinced the scientific world about the capabilities of a precisely guided missile.

After World War II, both the United States and the Soviet Union undertook their own cruise missile programmes. They were able to deploy cruise missiles land, aircraft and submarines within a few years time. The US Navy's submarine based missile SSM-N-8 Regulus was one of the early successes. It is known that in the late 50s the US tried developing a supersonic cruise missile that can deliver nuclear weapons, but was abandoned in favour of Inter Continental Ballistic Missiles (ICBMs).

Even as the ICBMs developed as the key nuclear delivery weapons for land targets, cruise missile emerged as the key missile against ships and carrier groups and for target specific attacks. The Soviet Union developed the Oscar and Echo class submarines that can carry cruise missiles to shadow the US battle groups.