A missile boat or missile cutter is a small, fast warship armed with anti-ship missiles. Being smaller than other warships such as destroyers and frigates, missile boats are popular with nations interested in forming a navy at lower cost. They are similar in concept to the torpedo boats of World War II; in fact, the first missile boats were modified torpedo boats with the torpedo tubes replaced by missile tubes.
The doctrine behind the use of missile boats is based on the principle of mobility over defence and firepower. The advent of proper guided missile and electronic countermeasure technologies gave birth to the idea that warships could now be designed to outmaneuver their enemies and conceal themselves while carrying powerful weapons.
Previously, increasing the potency of naval artillery required larger projectiles, which required larger and heavier guns, which in turn called for larger ships to carry these guns and their ammunition and absorb their recoil. This trend culminated in the giant battleships of World War II. Even as World War II was taking place, submarines and aircraft, particularly those launched from aircraft carriers, had made it clear that large warships were little more than targets in a major war. Guided bombs and then anti-ship missiles further reduced the usefulness of large warships outside the carriers.
Missile boats, when equipped with sophisticated anti-ship missiles, and especially when used in a swarm, can pose a significant threat to even the largest of capital ships, and do so at much greater ranges than is possible with torpedoes.