After studying WWI and WWII extensively last year, I was very interested by Hobsbawm discussion of nationalism in chapter 6. The many facets of the movement and the changes in the types of nationalism and its consequences was enlightening in terms of nationalism's role in starting these two wars as well as many other "problems" later.
One thing I am unclear about is why nationalism couldn't be used to rally everybody in the nation like it did in the subnational factions? If it united subgroups in a particular country, why couldn't nationalism be used to rally the country as a whole? I almost feel like there should be a world called ethnicity-ism, if this is the case.