The Astute class vessels, due to enter service with the Royal Navy in 2005, are expected to be the last submarines of their kind before a new generation of unmanned submersible weaponry takes over. Senior officers are examining a range of remote-controlled underwater robots that will revolutionise the force known as the "silent service". Manned submarines are expected to be used for command and transport roles rather than fighting sea battles, according to U.K. Ministry of Defence plans for the future of the Navy in the 21st century.

In place of traditional submarines in 15 to 20 years' time, the Navy is considering a range of nautical weaponry including robot drones that detect and destroy mines; unmanned intelligence-gathering underwater vehicles; and remote-controlled underwater missile and torpedo platforms. The weapons could be dropped into operations by aircraft or warships.

Discussion about the role of submarines in modern warfare follows widespread reappraisal of a whole range of weapons that dominated the battlefields, oceans and skies in 20th century conflicts. In similar moves, the Army has hinted that the heavy tank is to be superseded by lightweight vehicles with plastic armour while RAF chiefs plan to replace the Tornado bomber with a "Future Offensive Air Capability" after 2018, possibly an unmanned air vehicle or remote-controlled missile system.