Damn the uk-us relation is that bad? But then again with the BUP becoming more influental and north america basically in favour of the US no wonder the relation becominh more and more strainedI think this is Kennedy's gamble. He thought that Europe were better off by themselves, as Western Europe would definitely not befallen easily to the Soviet Union. With that, new powers would emerge to contest while the US will be busy on other regions. East Asia, on the other hand, is prone to ally China as their main Asian partner (not Japan due to WW2 sentiments).
About the Commonwealth vs the US, I think this is Kennedy's greatest decision to fully commited for a Pacific approach rather than Atlantic.
Besides, Kennedy's gamble due serve a benefit. The Soviet Union is now occupied with France, Germany and the mess in Europe while the US is strengthening ties all across Asia. Massive cons for the US is now India is a Chinese partner. And now, British-US relations has regressed back to 1812 era (although British HK remains friendly to the US)