Its an interesting idea, but just doesn't wash. The British Empire was bankrupt after WW1- that was the main reason for disarmament, and the theory that the war had been to defend the "rights of small nations" (ie, Belgium) was a major spur to nationalist movements in India, the Middle East (including Iraq), and not least Ireland, which gained independence in 1922. Moreover, it's interesting to note that the Britons most opposed to The British Empire were the socialists and communists who went to fight fascism in Spain, while the very people most committed to maintaining the Empire (Mosley's Blackshirts and the Conservative government, with the exception of Eden and Churchill)were those most favourably disposed to Hitler. Chamberlain, the Conservative Prime Minister, and Lord Halifax his Foreign Secretary negotiated the Munich agreement allowing Hitler to seize the Sudetenland from Czechoslovakia - the apogee of appeasement. Halifax in particular openly admired Hitler for his anti-communism, and described the Nazi regime in 1937 as "absolutely fantastic". I'm not sure what the lessons are here for the modern USA.
Good post Flora, although my analysis is a little more scathing, than yours; the diatribe at the beginning of this thread is simply a load of ignorant nonsense. The author clearly has absolutely no idea at all about the manner in which the British Empire came about, and hence why it ultimately fell to pieces.
And the British people had bloody good reason to feel antiwar after WWI; the vast majority of the lives lost were lost out of the pure military incompetence of a hopelessly old fashioned aristocratic command structure rather than necessary strategic advantage. In truth, the British were already getting tired of British foreign policy back during the Boer war, so the author isn't even right about that either!