In that time period, didn’t Britain also become a nation that was dependent on imports and had a massively declining manufacturing base?
-Joe
It wasn’t us, it was the Continentals 
. We just stuck by our treaty obligations.
Ooh nasty DIG,yes we are technically Europeans and I honestly am in favour of the E.C. but on an emotional level I’m an Englishman.
One of the reasons US forces were in Germany was to be a trip wire in case the russians started their world tour, along with your army of the rhine, invasion +1 minute and America was at war.
I think what you may be refering to is that the US would not risk an American city, for a fill in the blank european city against the soviets.
Declan
There was a great worry that the Soviets might have tried a" divide and conquer"
strategy.
Try to manipulate the U.S. public into a partial isolationist mindset plus rally anti British feeling along the lines of "Who do they think they are?Bloody colonialists,always expecting the Americans to bail them out when their in trouble etc.etc.
When this has been substantially established engineer a serious argument with the U.K. alone rather then with N.A.T.O. generally and when its apparent that the P.O.T.U.S. would be risking the public support of his own citizens if he fought the British corner as in “They got themselves into this mess,they can get themselves out”, land air and sea forces to secure U.K.airfields,ports and Command and Control centres but Not as an invasion and NOT as a full blown occupation, but as a temporary measure to prevent the crisis escalating into all out war.
Nukes would not be used though there would probably be a quite widespread use of nerve gas.
Of course the soviet "peace keeping forces"would withdraw as soon as the situation stabilised though in practice the forces would expand surrepticiously until the world became used to a Warsaw Pact occupied Britain,there would definitely be British citizens collaborating with the Russians from the extreme left of which, at that time there were many.
In time the occupation would become Fait Accompli and it would be pointless going to war after the fact.
The I.G.B. would not have been crossed so thats another pretext for war out of the way.
The result would be apart from losing a major N.A.T.O. player that there would be distrust amongst the treaty nations,maybe a reluctance to go to war if yet another country was knocked off and quite possibly some N.A.T.O. nations would start trying to appease the Soviet Union to make sure that they would’nt be next.
But H.M.G in its wisdom decided that any direct attack on the Brits,whether or not any other treaty nations were getting the same treatment would result in us doing our very best to wipe out European Russia before we ourselves became a smear on the landscape.