'The so-called continuous-at-sea-deterrence (CASD) has been the basis of Britain's strategic nuclear deterrent since the first Polaris submarines - the predecessor of Trident - were deployed in 1968.
But the RUSI paper, written by Professor Malcolm Chalmers - a former adviser to Jack Straw and Margaret Beckett when they were foreign secretaries - suggests CASD is no longer necessary following the end of the Cold War and abandoning it could produce "significant financial savings".
"There is now a stark gap between the assumptions on which planning for the UK's conventional and nuclear forces, respectively, are based," the paper said.
Dropping CASD would enable the government to delay ordering a replacement fleet of missile-carrying submarines, putting back the point where it would have to start paying out up to £1.5bn a year in construction costs, it argued.'
Mind you cancelling the whole programme would save billions more and help with wider disarmament.