The USA was gain influence by virtue of its wealth rather than its military. The RN is acting world cop, the USN is sufficient to show the flag and equal to the task of deterrence. We have no standing commitments once the Philippines gain independence, the USA has no intervention in Mexico, Haiti or the Banana wars, even if it does it takes barely more than two Brigades of Marines to quell any other American state. The Army never grows beyond a four Division force, likely never gets much more than a medium weight tank, by the 1950s it is all long in the tooth and rather out dated in doctrine. Even the Navy might atrophy without any need to project power since we have no global war, no cold War and our ships travel as neutrals. The PRC today sends money, invests, provides arms and advisers but has no genuine reach with traditional military power, its "Imperialism" is more a function of becoming the biggest trade partner, buying the minerals, mines or exports rather than standing off shore with a Carrier Battle Group.
Even the USSR floated on its natural wealth with a horridly inefficient economy, I think the Russians remain under industrialized despite having the population and wealth, ut I would still give them second biggest economy after the USA, third if the British Empire holds its together and is counted as one economy. I think they squander more on defense and prestige projects, the traditional corruption bleeds off he cream and the elite get comfy.
My bluetooth keyboard drops letters. I suggest he is a bachelor King, if he marries it is an English girl but he remains a gadfly and is reign is mediocre, without a war I doubt he is forced to abdicate and dies, George VII steps in to restore faith in the majesty that is the peerage. Without the American involvement in war there is less acceptability for American adventurers in London, I accept a butterfly sends the divorcee on another path.
Without instability in the Middle East or the threat from the USSR, I think the Europeans are not as pressed to restrict imports, especially the UK and Germany who have better supplies from Persia and the Ottomans, latter the Gulf and Arabia. A surviving OE is buying so the Pounds and Marks flow back better. I think congestion is more a problem for Europe so the era of big cars, cheap gas and the open road ends in the 1960s.