Introduction. The choice of Korea and Türkiye to analyze the behavior model within the framework of the changing international order is primarily due to such facts as maintaining close ties with Washington since their formation and their reference to each other as “brothers in blood”. Nevertheless, the historical paradigm of building the foreign policies has shown that there are some common directions that should be marked as “brotherhood in spirit”. The comparative analysis given in the article identifies the modern behavioral models of “the land of morning calm” and the Republic of Türkiye towards a changing geopolitical reality. The purpose of the study is to analyze the common points of intersection in the political processes of the two republics from the moment of their formation to the present days, also to identify the role of the “middle powers” during the Ukrainian crisis. Materials and Methods. The methods of induction and deduction, the method of content analysis, the method of comparison and analysis, and the statistical method as well as the civilizational approach were used in the research process. Due to the methods used, the authors of the article have managed to conduct a comparative analysis in these planes. The information base was made up of materials presented in news sources, statistical materials of international organizations, publications of scientists and experts. Results. A comprehensive country comparative analysis of states’ foreign policy trends in the XX and XXI centuries has been carried out, as well as their interaction with the “West” and the “westernization” of their course at the present stage – “brotherhood in spirit”. Also, the researchers have carried out main conclusions on their role of middle powers and regional actors due to the ongoing tectonic shifts in the international paradigm. Discussion and Сonclusion. Analyzing their “brotherhood in spirit” during the Ukrainian events, it is noted that Türkiye, in comparison with Korea, pursues a more independent course from the West, taking into account its own interests, while both are characterized by a “two-track” policy. Both states are taking a wait-and-see position in the conditions of the emerging political conjuncture of global interaction. The practical significance of the work is the analysis of the behavior of two countries – Korea and Türkiye – as “middle powers” in a changing world order. The obtained results can contribute to further study the role of this type of state in the “West–non-West” relationship.