This chapter assesses three colonization projects in Poland, Yugoslavia and Romania in the larger context of agrarian reforms in the interwar period and in 1944/5. It compares the reforms of the interwar years with those directly following World War II – the latter being the radicalized version of the former, acting as a laboratory of sorts for the collectivization and nationalization of land and property under state socialism. By focusing on colonization projects that took place between 1913 and 1950 in these countries, the chapter highlights the ethno-national dimension of agrarian reform and it shows that the role of the state in governing the rural grew consistently in this period. Both an economic and ethno-national perspective, this growing role of the state between the wars did not bring about the desired results. To the contrary, colonization projects' most obvious consequences were a significant worsening of interethnic relations in the region.