How did diversity cause nationalism to
rise in these different empires?

Diversity is a sociological concept that implies an ethnic, cultural and social mixture in a given society. In the past, before the rise of modern migratory currents, nations were characterized by their homogeneity, that is, by the fact that their inhabitants belonged in their vast majority to the same ethnocultural group, thus sharing physical, religious, social and cultural characteristics.

But as the world became interconnected, the population exchange between nations began. This was not well received in all of them, but in some cases immigration was seen as a threat to the aforementioned national values. For this reason, nationalist movements began to develop that began to promote the protection of these values, as well as the rejection of those values brought by immigrants.

the population grew a lot and was making more money

lots of people lost money in both