War for ideological reasons includes religious war and nationalist and racial war where an ideology is involved, as well as cold war and political conflict between ideologies.
Religious wars are currently taking place in Ulster and the Middle East. The war over Bangladesh had a religious basis and Indian/Pakistani border clashes also contain a religious war element. Ideological war between Capitalism and Communism took place in Korea and Vietnam. The Middle East war contains elements of racism and nationalism as well as religion.