Cain and Hopkins history of British Imperialism makes much use of the Nairn-Anderson thesis to describe the relationship between the 'Gentlemanly Capitalism' (ie feudalistic) of the City of London to explain imperialism.
Myself, I suspect that if the City of London was opposed to the First World War it was a reflection of the general attitude of the British Empire in the twentieth century that it had peaked, was overstretched, and could only lose out if there were disorder in the world. The same reasons lie behind appeasement of Hitler in the 1930s.
"Arno Mayer wrote a book, The Persistence of the Old Regime, arguing that given the bourgeoisie's opposition, WWI must be understood as the result of the vestigial hold of the aristocracy - with its inherited feudal war-for-territory mentality - on the state. He used a lot of cultural arguments about how the bourg still deferred to and emulated the nobles (like the obsession with horses and coats of arms.) Interesting book."