The special relationship

I can't offer a authoritative answer to this question, and I doubt that anyone who could would speak about it. However the very close collaboration between the UK and the USA that began in the dark days at the start of WWII continued throughout the war and through most of the Cold War.

From the perspective of the U.S. military, no other nation was as closely connected to our weapons development and strategic operations. We shared information on the design of nuclear weapons and ballistic missiles, highly classified reconnaissance operations, and the movements of our submarines that we shared with no other nation, or NATO for that matter. There were certainly elements of such close cooperation with other nations, for example Norway and Turkey, in the conduct of surveillance operations over the Soviet Union, but none were so broad and systematic as those with the UK.

We routinely exchanged officers on ships and squadrons. In the mid '70s I checked out in Buccaneers in 812 squadron on the old Arc Royal (the real carrier, the one with catapults), and served in US Navy squadrons with Royal Navy officers,

There were certainly moments of real friction and disagreement - Suez and Vietnam are the most prominent - however apart from them there was, as far as I could tell a very close and enduring relationship that went well beyond our formal alliances.