Fleet in being

In naval warfare, a fleet in being is a naval force that extends a controlling influence without ever leaving port. Were the fleet to leave port and face the enemy, it might lose in battle and no longer influence the enemy's actions, but by simply remaining safely in port the enemy is forced to continually deploy forces to guard against it. A fleet in being can be part of a sea denial doctrine but not one of sea control.

The term was first used in 1690, when Lord Torrington, commander of the Royal Navy forces in the English Channel, found himself facing a stronger French fleet. He proposed avoiding a set battle, except under very favourable conditions, until he could be reinforced. By thus keeping his 'fleet in being', he could maintain an active threat which would force the enemy to remain in the area and prevent them from taking the initiative elsewhere.

A more modern example is the stand-off between the German High Seas Fleet and the British Grand Fleet during World War I. Other than the inconclusive engagement at the Battle of Jutland, both Britain and Germany preferred to keep their fleets intact rather than taking the risk of losing an engagement.

In World War II, actions of the Italian Regia Marina in 1940 also demonstrate the idea of a 'fleet in being'. After a number of minor battles against the Royal Navy that were generally lost or drawn, the fleet was left in Taranto, where it could sortie very quickly against any British attempt to reach Malta. The effort was so successful that the British instead decided to attack their fleet at anchor during the famed Battle of Taranto. From that point on the Italians were forced into combat, and hence suffered repeated attrition over the next two years.

Even more so that other surface vessels in the Kriegsmarine, the German battleship Tirpitz served her entire career as a 'fleet in being'. Although she never fired a shot at an enemy ship, her mere presence forced the Royal Navy to allocate powerful warships in defending Arctic convoys.

Smaller nations also employed fleets in being, like the Finnish Navy with heavily armed coastal defence ships 'Väinämöinen' and 'Ilmarinen', whose mere existences prevented any Soviet attempts of invasion on Finland's southern coast and forced the strong Soviet navy and air force to play hide and seek in the Finnish archipelago.

Rudyard Kipling wrote a series of articles about the British Channel Fleet, collectively entitled A Fleet in Being and published in 1898; however, he used the term in more of a literal than a technical sense.