After World War I, according to the peace treaty of Rapallo Istria became part of Italy in 1920. Fascism and later Nazi occupation spoiled otherwise tolerant ethnic relations in the area. After World War II Istria was assigned to Yugoslavia and many ethnic Italians left in the Istrian exodus. With the collapse of Communist Yugoslavia Istria became part of an independent Croatia and the region saw no fighting in the ensuing war. Today it is one of the most economically developed parts of Croatia.