A3TK A.I.M. (Active Inert Missile) Polaris Missile, ca. 1970-79.

This missile was used by British submariners for training purposes. The Active Inert designation indicates it is a fully representational (Active) missile but carrying no warhead (Inert). This missile was used at the Faslane naval base in Scotland. Polaris was a United States submarine-launched ballistic missile (SLBM) capable of carrying nuclear warheads. Such submarine-based weapons system are relatively invulnerable owing to the enemy's uncertainty of knowing the submarines' positions at any one time. The Royal Navy operated Polaris in its Resolution class submarines between 1968 and 1986. Polaris underpinned the UK and NATO's policy of strategic deterrence in which the possession of such weapons systems would disuade the enemy from mounting a pre-emptive attack; the cost to an enemy of attacking the UK would outweigh any benefit they could hope to gain by doing so.