All this talk of Marxism has re-kindled long-lost learning. If I'm correct (and I'm willing to be proven wrong), Marx was actually writing a manifesto for the German Socialist Workers Party (not NSDAP!) in 1848 whilst staying in a house owned by Engels which was, and this is the interesting point, paid for from the profits of Lancashire cotton mills. Therefore, Marxism directly benefited (it can be alleged) from the British Empire.
In any case, the special relationship was only ever beneficial to the US. Why? Britain was one of the safest bets for post-war overseas bases and given that Britain had relied on US financial and industrial support during WW2, was fairly much tied into whatever the US wanted. One only has to look at the way in which America pulled the plug on the dissemination of nuclear techology to the UK in 1946 to see which way the relationship went.