In 1973 when the UK joined the European Economic Community it had to impose tariffs on Commonwealth countries, put in VAT and confine its free trade ambitions to the European continent. There was a sense of betrayal in New Zealand and Australia where they saw Europe replace themselves in crucial export areas like food. The UK was brusque and unhelpful to those countries that had done most to stand by Britain, especially during the long and brutal second world war when the UK was fighting against Germany and Italy, two founders of the EEC.
Winston Churchill put out may ideas about the future and about how the world might develop. He did envisage a European Union, though any careful reading of the relevant speeches makes clear that was for the continental countries and did not include the UK herself. His work has been much traduced since by those who claim he was an early pioneer of the EU. To reinforce the point Churchill wrote a long four volume history of the "English speaking peoples", not of the Europeans. That concluded that he thought there would be a union of the English speaking peoples and it would begin as a defence alliance. All his life he had closest affinity with the English speaking world, from his family and strong political links with the USA through his early adult life in South Africa to his passions for Empire and then for Commonwealth.
Today this takes shape. The UK is a member of the five country 5 Eyes alliance for sharing deepest intelligence with the USA, Canada, Australia and New Zealand that goes beyond what NATO members share. There is the 3 country Pacific AUKUS defence alliance with the USA and Australia. The USA and UK have been the leaders of NATO, given the French on off involvement and wish to create a separate EU defence arrangement. The TPP with a services chapter missing from many EU trade deals is more suited to the UK needs and may attract the USA as a member to join the UK, New Zealand and Australia.