What is one main reason some governments in the twentieth century began campaigns of genocide?

Governments have sometimes targeted groups for genocide because they viewed the groups’ different cultures, identities, or customs as a threat to national unity or their power. This makes “a minority group had different cultural customs” the best answer. Calls for independence, political representation, or protests can lead to conflict or repression, but they are not the general reason described here.

AI-written and checked against the verified answer.