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 while it remains 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 sea 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.

Rudyard Kipling published a series of articles about the British Channel Fleet under the title A Fleet in Being in 1898, but did not use the term in the sense described here.

The "fleet in being" concept is based on the assumption that the fleet is relatively safe in port, even if near the enemy. After the battle of Taranto and the attack on Pearl Harbor, however, it became obvious that air power made a fleet concentrated in a port vulnerable, and a fleet in being was normally no longer a safe option. It is, of course, possible to imagine a situation where a fleet is still relatively safe in harbour, such as the opponent being unwilling to attack them in harbour for political reasons. After looking at the alternatives; "The strategy that was accepted for the Argentine Navy [in the 1982 Falklands War] was one of a 'fleet in being' concept ... The fleet would not conduct a direct attack; they would only attack when the odds were in their favor. Otherwise they would remain outside any declared British exclusion zones and wait for a target of opportunity". The Argentinians were not able to make any positive use of their "fleet in being" but they did avoid a negative result.

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Wikipedia