The secret conference was about Polaris submarines. The UGM-27 (Polaris) was a two-stage submarine-launched thernonuclear-warheaded missile and submarines capable of launching them were called Polaris subs. In 1964 the UK began construction of four Resolution-class subs each capable of carrying 16 Polaris missiles. The program became operational two years after this episode aired.
Warren Mitchell returned as the hapless Brodny in the following season's The See-Through Man (1967).