During the Breakup of Yugoslavia, Marković considered that the borders of the country should be changed based on ethnic and historical grounds. Marković considered that Republic of Serbian Krajina, eastern Slavonia, Baranja and western Srem should not belong to Croatia because the Serbian people have lived in these territories for most of the centuries. He also considered that "the Albanian people lack any historical reasons to support their right to Kosovo", as they did not live in the territory before the arrival of the Slavs.