Answer:
Increasing feelings of nationalism among many groups led to the rise of fascism.
Step-by-step explanation:
One very negative consequence of increased feelings of nationalism after WWI was the rise of fascism or so-called national socialism in countries like Germany and Italy. These governments appealed to nationalism and blamed such groups as the Jewish people for their economic problems in the late 20's and early 30's and also believed they had the right to invade and control other countries.
Fascism was a political, economic and social system that gained momentum after the First World War, especially in countries in economic crisis (Italy and Germany).