Fleet in being

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.

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.

While this is not necessarily true in the modern era, for much of human history a fleet that was at harbor was much less exposed to attack and to other hazards such as storms.

This creates a stalemate that favours the defender because the attacker always must deploy a superior force to counter them, and those units are unable to perform any other duties.

A port is a known location for an enemy to focus attacks on and a handful of aircraft or submarines can damage or sink multiple warships, even in the presence of advanced defenses.

A fortress under siege is essentially an "army in being", which ties up enemy forces without taking the risk of fighting a battle.

[9] Although this last attempt also failed, it had the unintended consequence of robbing the Russian Navy of one of its most brilliant naval officers, Admiral Stepan Makarov.

The "fleet in being" remained so, until under the new command of Admiral Vilgelm Vitgeft, the Port Arthur squadron was ordered to break out and steam for Vladivostok on 10 August 1904.

[12] Even more so than other surface vessels in Nazi Germany's Kriegsmarine (navy), the German battleship Tirpitz served her entire career as a "fleet in being" in her own right.

Although remarkably she never fired a shot at an enemy ship, her mere presence in the Norwegian fiords forced the Royal Navy and their allies to allocate powerful warships in defending Arctic convoys, and caused a major convoy (PQ 17) to scatter, suffering huge losses, mainly to U-boats and aircraft.

A 1943 midget submarine attack and successive airstrikes launched by the RAF and the Fleet Air Arm removed the threat by November 1944, when the Tirpitz was sunk at Tromsø by Lancaster bombers.