Complex sentence: Unlike other nationalities in Iraq, Chaldeans doesnt have national activity after the founding of the Iraqi state, There was some Chaldeans, who was have a nationalist ideas like Bishop Addai Scher, author of Caldo Athor book, who spoke about the Chaldean nationalism.
Split into simpler sentences: Unlike other nationalities in Iraq, Chaldeans generally did not have nationalist objectives after the founding of the Iraqi state. However nationalist ideals were held by a minority, most noteably by Bishop Addai Scher, author of Caldo Athor book, who spoke about Chaldean nationalism.